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Han JH, Shin DY, Sung C, Cho SH, Ju BK, Chung KB, Nam S. Tuning the Threshold Voltage of an Oxide Thin-Film Transistor by Electron Injection Control Using a p-n Semiconductor Heterojunction Structure. ACS APPLIED MATERIALS & INTERFACES 2024; 16:31254-31260. [PMID: 38856760 DOI: 10.1021/acsami.4c02681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Herein, a heterojunction structure integrating p-type tellurium (Te) and n-type aluminum-doped indium-zinc-tin oxide (Al:IZTO) is shown to precisely modulate the threshold voltage (VT) of the oxide thin-film transistor (TFT). The proposed architecture integrates Te as an electron-blocking layer and Al:IZTO as a charge-carrier transporting layer, thereby enabling controlled electron injection. The effects of incorporating the Te layer onto Al:IZTO are investigated, with a focus on X-ray photoelectron spectroscopy (XPS) analysis, in order to explain the behavior of oxygen vacancies and to depict the energy band structure configurations. By modulating the thickness and employing both single and double deposition methods for the heterojunction Te layer, a remarkable VT shift of up to +20 V is achieved. Furthermore, this study also shows excellent stability to a positive bias stress of +2 MV/cm for 10,000 s without additional passivation layers, demonstrating the robustness of the designed TFT. By a thorough optimization of the Al:IZTO/Te interface, the results demonstrate not only the substantial impact of the introduced heterojunction structure on VT control but also the endurance, durability, and stability of the optimized TFTs under prolonged long-term operating stress, thus offering promising prospects for tailored semiconductor device applications.
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Affiliation(s)
- Jung Hoon Han
- Flexible Electronic Device Research Division, Electronics and Telecommunications Research Institute, 218, Yuseong-gu, Daejeon 34129, Korea
- Department of Micro/Nano System, Korea University, Seongbuk-gu, Seoul 136-713, Korea
| | - Dong Yeob Shin
- Division of Physics and Semiconductor Science, Dongguk University, Jung-gu, Seoul 04620, Korea
| | - Chihun Sung
- Flexible Electronic Device Research Division, Electronics and Telecommunications Research Institute, 218, Yuseong-gu, Daejeon 34129, Korea
| | - Sung Haeng Cho
- Flexible Electronic Device Research Division, Electronics and Telecommunications Research Institute, 218, Yuseong-gu, Daejeon 34129, Korea
| | - Byeong-Kwon Ju
- Department of Micro/Nano System, Korea University, Seongbuk-gu, Seoul 136-713, Korea
| | - Kwun-Bum Chung
- Division of Physics and Semiconductor Science, Dongguk University, Jung-gu, Seoul 04620, Korea
| | - Sooji Nam
- Flexible Electronic Device Research Division, Electronics and Telecommunications Research Institute, 218, Yuseong-gu, Daejeon 34129, Korea
- Semiconductor and Advanced Device Engineering, University of Science and Technology, 217, Yuseong-gu, Daejeon 305-350, Korea
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Sharma M, Adalati R, Kumar A, Mehta M, Chandra R. Composite Assembling of Oxide-Based Optically Transparent Electrodes for High-Performance Asymmetric Supercapacitors. ACS APPLIED MATERIALS & INTERFACES 2022; 14:26791-26802. [PMID: 35656926 DOI: 10.1021/acsami.2c05189] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Simultaneously achieving a transparent and high-energy density supercapacitor is a major challenge because of the trade-off between energy storage capacity and optical transparency of active electrode materials. Herein, we demonstrate a novel approach to construct an optically transparent asymmetric supercapacitor (Trans-ASC) by assembling positive (ZnO-SnO2) and negative (TiO2-SnO2) composite thin-film electrodes on a conductive indium-doped tin oxide substrate via reactive DC magnetron cosputtering. The optical transmittance for both composite thin films is found to be 68% (ZnO-SnO2) and 64% (TiO2-SnO2). Furthermore, electrochemical kinematics of the primed transparent electrodes are scrutinized in 0.5 M KOH electrolyte without affecting the transparency of active electrodes. The structural reliability of the electrodes aids the superb electrochemical performance to construct a Trans-ASC, TiO2-SnO2//ZnO-SnO2, which works at a voltage of +1.2 V and attains a higher areal capacitance of 44.6 mF cm-2 at 2 mA cm-2. The assembled Trans-ASC delivers a maximum areal energy density of 8.75 μW h cm-2 with an optimal areal power density of 570 μW cm-2. Additionally, the capacitance retention of 81.6% and transparency of both electrodes remain almost the same (up to 60% for ZnO-SnO2 and 62% for TiO2-SnO2) even after 10,000 charging-discharging cycles. These remarkable electrochemical properties and outstanding cycling stability of the designed Trans-ASC device make it a potential candidate for storing energy and for further use in transparent electronic devices.
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Affiliation(s)
- Meenakshi Sharma
- Nano Science Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
- Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
| | - Ravikant Adalati
- Nano Science Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
| | - Ashwani Kumar
- Nano Science Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
| | - Manan Mehta
- Department of Electrical and Electronics Engineering, University of Petroleum and Energy Studies, Bidholi, Dehradun 248007, Uttarakhand, India
| | - Ramesh Chandra
- Nano Science Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
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Dhara S, Niang KM, Flewitt AJ, Nathan A, Lynch SA. Tail state mediated conduction in zinc tin oxide thinfilm phototransistors under below bandgap optical excitation. Sci Rep 2021; 11:19016. [PMID: 34561512 PMCID: PMC8463548 DOI: 10.1038/s41598-021-98339-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/24/2021] [Indexed: 11/10/2022] Open
Abstract
We report on the appearance of a strong persistent photoconductivity (PPC) and conductor-like behaviour in zinc tin oxide (ZTO) thinfilm phototransistors. The active ZTO channel layer was prepared by remote plasma reactive sputtering and possesses an amorphous structure. Under sub-bandgap excitation of ZTO with UV light, the photocurrent reaches as high as ~ 10-4 A (a photo-to-dark current ratio of ~ 107) and remains close to this high value after switching off the light. During this time, the ZTO TFT exhibits strong PPC with long-lasting recovery time, which leads the appearance of the conductor-like behaviour in ZTO semiconductor. In the present case, the conductivity changes over six orders of magnitude, from ~ 10-7 to 0.92/Ω/cm. After UV exposure, the ZTO compound can potentially remain in the conducting state for up to a month. The underlying physics of the observed PPC effect is investigated by studying defects (deep states and tail states) by employing a discharge current analysis (DCA) technique. Findings from the DCA study reveal direct evidence for the involvement of sub-bandgap tail states of the ZTO in the strong PPC, while deep states contribute to mild PPC.
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Affiliation(s)
- Soumen Dhara
- School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, UK.,Faculty of Science, Sri Sri University, Cuttack, 754006, India
| | - Kham M Niang
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Andrew J Flewitt
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Arokia Nathan
- Darwin College, University of Cambridge, Cambridge, CB3 9EU, UK
| | - Stephen A Lynch
- School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, UK.
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Zhang W, Zhang D, Yan W, Luo W, Zhao C, Liu D. Optically Induced Rapid Wetting Transition on Zn-Polar and O-Polar Zinc Oxide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14791-14796. [PMID: 31663342 DOI: 10.1021/acs.langmuir.9b02629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The design and fabrication of surfaces that support rapid wetting transition remain technologically challenging. Here, we examine the effects of optical illumination on the wetting behaviors of zinc oxide (ZnO) single crystals. We find that ultraviolet irradiation above the band gap energy promotes a rapid wetting transition, characterized by sliding of the water droplet, within a few seconds. Notably, the transition for Zn-polar (0001) ZnO surfaces is even faster than that for O-polar (0001̅) ZnO surfaces. We confirmed that process is dependent on power, surface polarity, and solution pH and reversible through illumination by near-infrared light, which restores the water contact angle back to its initial value. Surface chemical analysis revealed that the instantaneous photocatalytic formation of surface-terminated hydroxyl (-OH) groups is responsible for the observed rapid wetting transition. Density functional theory calculations with the inclusion of onsite Coulomb interactions revealed that both the Zn-polar and O-polar surfaces can be easily covered with -OH groups through the adsorption of -OH groups or hydrogen atoms, respectively. This study develops a route to fabricate optically active and controllable microfluidic devices that support rapid wetting transitions for water droplet manipulation.
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Affiliation(s)
- Wangyang Zhang
- State Key Laboratory of Crystal Materials , Shandong University , 27 South Shanda Road , Jinan , Shandong 250100 , P. R. China
| | - Dongdong Zhang
- State Key Laboratory of Crystal Materials , Shandong University , 27 South Shanda Road , Jinan , Shandong 250100 , P. R. China
| | - Weishan Yan
- State Key Laboratory of Crystal Materials , Shandong University , 27 South Shanda Road , Jinan , Shandong 250100 , P. R. China
| | - Wenyao Luo
- State Key Laboratory of Crystal Materials , Shandong University , 27 South Shanda Road , Jinan , Shandong 250100 , P. R. China
| | - Chaopeng Zhao
- State Key Laboratory of Crystal Materials , Shandong University , 27 South Shanda Road , Jinan , Shandong 250100 , P. R. China
| | - Duo Liu
- State Key Laboratory of Crystal Materials , Shandong University , 27 South Shanda Road , Jinan , Shandong 250100 , P. R. China
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Kim T, Kim MJ, Lee J, Jeong JK. Boosting Carrier Mobility in Zinc Oxynitride Thin-Film Transistors via Tantalum Oxide Encapsulation. ACS APPLIED MATERIALS & INTERFACES 2019; 11:22501-22509. [PMID: 31190521 DOI: 10.1021/acsami.9b03865] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Novel TaO x encapsulation was presented to enhance the field-effect mobility (μFE) of ZnON thin-film transistors (TFTs) consisting of a metallic Ta film deposited onto the ZnON surface followed by a modest annealing process. The resulting TaO x/ZnON film stack exhibited a more uniform distribution of nanoscale ZnON crystallites with increased stoichiometric anion lattices compared to the control ZnON film. The control ZnON TFTs exhibited a reasonable μFE, subthreshold gate swing (SS), and ION/OFF ratio of 36.2 cm2/V·s, 0.28 V/decade, and 2.9 × 108, respectively. A significantly enhanced μFE value of 89.4 cm2/V·s was achieved for ZnON TFTs with a TaO x encapsulation layer, whereas the SS of 0.33 V/decade and ION/OFF ratio of 8.6 × 108 were comparable to those of the control device. This improvement could be explained by scavenging and passivation effects of the TaO x film on the ZnON channel layer. Density of states (DOS)-based modeling and simulation were performed to obtain greater insight with regard to increasing the performance of the ZnON TFTs with a TaO x encapsulation layer. A smaller number of subgap states near the conduction band (CB) minimum and a higher net carrier density for the TaO x-capped device increased the Fermi energy level toward the CB edge under thermal equilibrium conditions, leading to efficient band conduction and fast carrier transport under the on-state condition.
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Affiliation(s)
- Taeho Kim
- Department of Electronic Engineering , Hanyang University , Seoul 133-791 , South Korea
| | - Min Jae Kim
- Department of Electronic Engineering , Hanyang University , Seoul 133-791 , South Korea
| | - Jiwon Lee
- Department of Electronic Engineering , Hanyang University , Seoul 133-791 , South Korea
| | - Jae Kyeong Jeong
- Department of Electronic Engineering , Hanyang University , Seoul 133-791 , South Korea
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Xu H, Xu M, Li M, Chen Z, Zou J, Wu W, Qiao X, Tao H, Wang L, Ning H, Ma D, Peng J. Trap-Assisted Enhanced Bias Illumination Stability of Oxide Thin Film Transistor by Praseodymium Doping. ACS APPLIED MATERIALS & INTERFACES 2019; 11:5232-5239. [PMID: 30640426 DOI: 10.1021/acsami.8b18329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Praseodymium-doped indium zinc oxide (PrIZO) has been employed as the channel layer of thin-film transistors (TFTs). The TFTs with Pr doping exhibited a remarkable suppression of the light-induced instability. A negligible photo-response and remarkable enhancement in negative gate bias stress under illumination (NBIS) were achieved in the PrIZO-TFTs. Meanwhile, the PrIZO-TFTs showed reasonable characteristics with a high-field-effect mobility of 26.3 cm2/V s, SS value of 0.28 V/decade, and Ion/ Ioff ratio of 108. X-ray photoelectron spectroscopy, microwave photoconductivity decay, and photoluminescence spectra were employed to analyze the effects of the Pr concentrations on the performance of PrIZO-TFTs. We disclosed that acceptor-like trap states induced by Pr ions might lead to the suppression of photo-induced carrier in conduction band, which is a new strategy for improving illumination stability of amorphous oxide semiconductors. Finally, a prototype of fully transparent AMOLED display was successfully fabricated to demonstrate the potential of Pr-doping TFTs applied in transparent devices.
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Affiliation(s)
- Hua Xu
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Miao Xu
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Min Li
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Zikai Chen
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Jianhua Zou
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Weijing Wu
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Xianfeng Qiao
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Hong Tao
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Lei Wang
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Honglong Ning
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Junbiao Peng
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
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7
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All-Sputtering, High-Transparency, Good-Stability Coplanar Top-Gate Thin Film Transistors. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app9010083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In this work, transparent, stable coplanar top-gate thin film transistors (TFTs) with an active layer of neodymium-doped indium oxide and zinc oxide (Nd-IZO) were successfully fabricated on a glass substrate by all sputtering processes. The devices with a post-annealing temperature of 400 °C exhibited good electrical performances with a saturation mobility (μsat) of 4.25 cm2·V−1·S−1, Ion/Ioff ratio about 106, Vth of −0.97 V and SS about 0.34 V/decade. Furthermore, the devices exhibited excellent negative and positive bias stability (NBS, PBS) of only a ΔVth shift of about −0.04 V and 0.05 V after 1 h, respectively. In addition, the devices showed high transparency about 96% over the visible-light region of 400–700 nm, which indicates a great potential in transparent displays.
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Hwang ES, Kim JS, Jeon SM, Lee SJ, Jang Y, Cho DY, Hwang CS. In 2Ga 2ZnO 7 oxide semiconductor based charge trap device for NAND flash memory. NANOTECHNOLOGY 2018; 29:155203. [PMID: 29420311 DOI: 10.1088/1361-6528/aaadf7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The programming characteristics of charge trap flash memory device adopting amorphous In2Ga2ZnO7 (a-IGZO) oxide semiconductors as channel layer were evaluated. Metal-organic chemical vapor deposition (MOCVD) and RF-sputtering processes were used to grow a 45 nm thick a-IGZO layer on a 20 nm thick SiO2 (blocking oxide)/p++-Si (control gate) substrate, where 3 nm thick atomic layer deposited Al2O3 (tunneling oxide) and 5 nm thick low-pressure CVD Si3N4 (charge trap) layers were intervened between the a-IGZO and substrate. Despite the identical stoichiometry and other physicochemical properties of the MOCVD and sputtered a-IGZO, a much faster programming speed of MOCVD a-IGZO was observed. A comparable amount of oxygen vacancies was found in both MOCVD and sputtered a-IGZO, confirmed by x-ray photoelectron spectroscopy and bias-illumination-instability test measurements. Ultraviolet photoelectron spectroscopy analysis revealed a higher Fermi level (E F) of the MOCVD a-IGZO (∼0.3 eV) film than that of the sputtered a-IGZO, which could be ascribed to the higher hydrogen concentration in the MOCVD a-IGZO film. Since the programming in a flash memory device is governed by the tunneling of electrons from the channel to charge trapping layer, the faster programming performance could be the result of a higher E F of MOCVD a-IGZO.
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Affiliation(s)
- Eun Suk Hwang
- Department of Materials Science & Engineering, and Inter-University Semiconductor Research Center, Seoul National University, Seoul, 151-744, Republic of Korea
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Jung H, Kim WH, Park BE, Woo WJ, Oh IK, Lee SJ, Kim YC, Myoung JM, Gatineau S, Dussarrat C, Kim H. Enhanced Light Stability of InGaZnO Thin-Film Transistors by Atomic-Layer-Deposited Y 2O 3 with Ozone. ACS APPLIED MATERIALS & INTERFACES 2018; 10:2143-2150. [PMID: 29277990 DOI: 10.1021/acsami.7b14260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the effect of Y2O3 passivation by atomic layer deposition (ALD) using various oxidants, such as H2O, O2 plasma, and O3, on In-Ga-Zn-O thin-film transistors (IGZO TFTs). A large negative shift in the threshold voltage (Vth) was observed in the case of the TFT subjected to the H2O-ALD Y2O3 process; this shift was caused by a donor effect of negatively charged chemisorbed H2O molecules. In addition, degradation of the IGZO TFT device performance after the O2 plasma-ALD Y2O3 process (field-effect mobility (μ) = 8.7 cm2/(V·s), subthreshold swing (SS) = 0.77 V/dec, and Vth = 3.7 V) was observed, which was attributed to plasma damage on the IGZO surface adversely affecting the stability of the TFT under light illumination. In contrast, the O3-ALD Y2O3 process led to enhanced device stability under light illumination (ΔVth = -1 V after 3 h of illumination) by passivating the subgap defect states in the IGZO surface region. In addition, TFTs with a thicker IGZO film (55 nm, which was the optimum thickness under the current investigation) showed more stable device performance than TFTs with a thinner IGZO film (30 nm) (ΔVth = -0.4 V after 3 h of light illumination) by triggering the recombination of holes diffusing from the IGZO surface to the insulator-channel interface. Therefore, we envisioned that the O3-ALD Y2O3 passivation layer suggested in this paper can improve the photostability of TFTs under light illumination.
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Affiliation(s)
- Hanearl Jung
- School of Electrical and Electronic Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
| | - Woo-Hee Kim
- Division of Advanced Materials Engineering, Chonbuk National University , 567 Baekje-daero, deokjin-gu, Jeonju-si, Jeollabuk-do 54896, Republic of Korea
| | - Bo-Eun Park
- School of Electrical and Electronic Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
| | - Whang Je Woo
- School of Electrical and Electronic Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
| | - Il-Kwon Oh
- School of Electrical and Electronic Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
| | - Su Jeong Lee
- Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
| | - Yun Cheol Kim
- Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
| | - Jae-Min Myoung
- Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
| | - Satoko Gatineau
- Air Liquide Korea Co., LTD . 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | | | - Hyungjun Kim
- School of Electrical and Electronic Engineering, Yonsei University , 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, Republic of Korea
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Nam YH, Kim DH, Shinde SS, Song JW, Park MJ, Yu JY, Lee JH. Planar n-Si/PEDOT:PSS hybrid heterojunction solar cells utilizing functionalized carbon nanoparticles synthesized via simple pyrolysis route. NANOTECHNOLOGY 2017; 28:475402. [PMID: 29086756 DOI: 10.1088/1361-6528/aa9014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Herein, we present a facile and simple strategy for in situ synthesis of functionalized carbon nanoparticles (CNPs) via direct pyrolysis of ethylenediaminetetraacetic acid (EDTA) on silicon surface. The CNPs were incorporated in hybrid planar n-Si and poly(3,4-etyhlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solar cells to improve device performance. We demonstrate that the CNPs-incorporated devices showed increased electrical conductivity (reduced series resistance) and minority carrier lifetime (better charge carrier collection) than those of the cells without CNPs due to the existence of electrically conductive sp 2-hybridized carbon at the heterojunction interfaces. With an optimal concentration of CNPs, the hybrid solar cells exhibited power conversion efficiency up to 11.95%, with an open-circuit voltage of 614 mV, short-circuit current density of 26.34 mA cm-2, and fill factor of 73.93%. These results indicate that our approach is promising for the development of highly efficient organic-inorganic hybrid solar cells.
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Affiliation(s)
- Yoon-Ho Nam
- Department of Materials and Chemical Engineering, Hanyang University, Ansan, Kyounggi 15588, Republic of Korea
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Li J, Tang W, Liu G, Li W, Deng Y, Yang J, Chen Y. Reduced graphene oxide modified platinum catalysts for the oxidation of volatile organic compounds. Catal Today 2016. [DOI: 10.1016/j.cattod.2015.09.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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12
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Activation of sputter-processed indium-gallium-zinc oxide films by simultaneous ultraviolet and thermal treatments. Sci Rep 2016; 6:21869. [PMID: 26902863 PMCID: PMC4763207 DOI: 10.1038/srep21869] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/02/2016] [Indexed: 11/12/2022] Open
Abstract
Indium–gallium–zinc oxide (IGZO) films, deposited by sputtering at room temperature, still require activation to achieve satisfactory semiconductor characteristics. Thermal treatment is typically carried out at temperatures above 300 °C. Here, we propose activating sputter- processed IGZO films using simultaneous ultraviolet and thermal (SUT) treatments to decrease the required temperature and enhance their electrical characteristics and stability. SUT treatment effectively decreased the amount of carbon residues and the number of defect sites related to oxygen vacancies and increased the number of metal oxide (M–O) bonds through the decomposition-rearrangement of M–O bonds and oxygen radicals. Activation of IGZO TFTs using the SUT treatment reduced the processing temperature to 150 °C and improved various electrical performance metrics including mobility, on-off ratio, and threshold voltage shift (positive bias stress for 10,000 s) from 3.23 to 15.81 cm2/Vs, 3.96 × 107 to 1.03 × 108, and 11.2 to 7.2 V, respectively.
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Xiao H, Zhu LQ, Liu YH, Liu R. Proton gated oxide electric-double-layer transistors for full-swing low voltage inverter applications. RSC Adv 2016. [DOI: 10.1039/c5ra23155h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Low voltage full-swing inverters were built by connecting proton gated oxide electric-double-layer transistors in series with resistors.
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Affiliation(s)
- Hui Xiao
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo 315201
- People's Republic of China
| | - Li Qiang Zhu
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo 315201
- People's Republic of China
| | - Yang Hui Liu
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo 315201
- People's Republic of China
| | - Rui Liu
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo 315201
- People's Republic of China
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Yun MG, Ahn CH, Cho SW, Kim SH, Kim YK, Cho HK. Dual electrical behavior of multivalent metal cation-based oxide and its application to thin-film transistors with high mobility and excellent photobias stability. ACS APPLIED MATERIALS & INTERFACES 2015; 7:6118-6124. [PMID: 25714371 DOI: 10.1021/am5085836] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effect of multivalent metal cations, including vanadium(V) and tin (Sn), on the electrical properties of vanadium-doped zinc tin oxide (VZTO) was investigated in the context of the fabrication of thin-film transistors (TFTs) using a single VZTO film and VZTO/ZTO bilayer as channel layers. The single VZTO TFT did not show any response to the gate voltage (insulator-like behavior). On the other hand, the VZTO/ZTO bilayer TFT exhibited a typical TFT transfer characteristic (semiconducting behavior). X-ray photoelectron spectroscopy revealed that, in contrast to what is commonly true in many oxides, oxygen vacancies (V(O)) in VZTO did not provide a dominant contribution to the total carrier concentration, because the V(O) peak area in the single VZTO film was 5.4% and reduced to 4.5% in VZTO/ZTO bilayer. Instead, Sn 3d5/2 and V 2p3/2 spectra suggest that the significant reduction in Sn and V ions is strongly related to the insulator-like behavior of the VZTO film. In negative-bias illumination tests and illumination tests with various photon energies, the VZTO/ZTO bilayer TFT had much better stability than the ZTO TFT. This result is attributed to the reduction of donor-like states ([Formula: see text]O) that can be positively ionized by blue and green illumination.
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Affiliation(s)
- Myeong Gu Yun
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746, Korea
| | - Cheol Hyoun Ahn
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746, Korea
| | - Sung Woon Cho
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746, Korea
| | - So Hee Kim
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746, Korea
| | - Ye Kyun Kim
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746, Korea
| | - Hyung Koun Cho
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746, Korea
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Kim YJ, Oh S, Yang BS, Han SJ, Lee HW, Kim HJ, Jeong JK, Hwang CS, Kim HJ. Impact of the cation composition on the electrical performance of solution-processed zinc tin oxide thin-film transistors. ACS APPLIED MATERIALS & INTERFACES 2014; 6:14026-14036. [PMID: 25090286 DOI: 10.1021/am503351e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This study examined the structural, chemical, and electrical properties of solution-processed (Zn,Sn)O3 (ZTO) films with various Sn/[Zn+Sn] ratios for potential applications to large-area flat panel displays. ZTO films with a Zn-rich composition had a polycrystalline wurtzite structure. On the other hand, the Sn-rich ZTO films exhibited a rutile structure, where the Zn atom was speculated to replace the Sn site, thereby acting as an acceptor. In the intermediate composition regions (Sn/[Zn+Sn] ratio from 0.28 to 0.48), the ZTO films had an amorphous structure, even after annealing at 450 °C. The electrical transport properties and photobias stability of ZTO thin film transistors (TFTs) were also examined according to the Sn/[Zn+Sn] ratio. The optimal transport property of ZTO TFT was observed for the device with an amorphous structure at a Sn/[Zn+Sn] ratio of 0.48. The mobility, threshold voltage, subthreshold swing, and on/off current ratio were 4.3 cm(2)/(V s), 0 V, 0.4 V/decade, and 4.1 × 10(7), respectively. In contrast, the device performance for the ZTO TFTs with either a higher or lower Sn concentration suffered from low mobility and a high off-state current, respectively. The photoelectrical stress measurements showed that the photobias stability of the ZTO TFTs was improved substantially when the ZTO semiconducting films had a lower oxygen vacancy concentration and an amorphous structure. The relevant rationale is discussed based on the phototransition and subsequent migration mechanism from neutral to positively charged oxygen vacancies.
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Affiliation(s)
- Yoon Jang Kim
- Department of Materials Science and Engineering, and Inter-university Semiconductor Research Center, Seoul National University , Seoul 151-742, Republic of Korea
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Kwon JM, Jung J, Rim YS, Kim DL, Kim HJ. Improvement in negative bias stress stability of solution-processed amorphous In-Ga-Zn-O thin-film transistors using hydrogen peroxide. ACS APPLIED MATERIALS & INTERFACES 2014; 6:3371-3377. [PMID: 24503476 DOI: 10.1021/am4054139] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We have investigated the effect of hydrogen peroxide (H2O2) on negative bias stress (NBS) stability of solution-processed amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). The instability of solution-processed a-IGZO TFTs under NBS is attributed to intrinsic oxygen vacancy defects (Vo) and organic chemical-induced defects, such as pores, pin holes, and organic residues. In this respect, we added H2O2 into an indium-gallium-zinc oxide solution to reduce the defects without any degradation of electrical performance. The field-effect mobility and sub-threshold slope of the a-IGZO TFTs were improved from 0.37 cm(2) V(-1) s(-1) and 0.86 V/dec to 0.97 cm(2) V(-1) s(-1) and 0.58 V/dec, respectively. Furthermore, the threshold voltage shift under NBS was dramatically decreased from -3.73 to -0.18 V. These results suggest that H2O2 effectively reduces Vo through strong oxidation and minimizes organic chemical-induced defects by eliminating the organic chemicals at lower temperatures compared to a conventional solution process.
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Affiliation(s)
- Jeong Moo Kwon
- School of Electrical and Electronic Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Korea
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Zhang J, Li X, Lu J, Zhou N, Guo P, Lu B, Pan X, Chen L, Ye Z. Water assisted oxygen absorption on the instability of amorphous InAlZnO thin-film transistors. RSC Adv 2014. [DOI: 10.1039/c3ra44513e] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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