The Effects of Temperature on the Growth of a Lead-Free Perovskite-Like (CH3NH3)3Sb2Br9 Single Crystal for An MSM Photodetector Application

Properties and alcohol sensing applications of quasi-2D (PEA)2(MA)3Sb2Br9 thin films

We fabricated an alcohol detector based on (PEA)₂(CH₃NH₃)₃Sb₂Br₉ ((PEA)₂MA₃Sb₂Br₉) lead-free perovskite-like films. The XRD pattern revealed that the (PEA)₂MA₃Sb₂Br₉ lead-free perovskite-like films exhibited a quasi-2D structure. The optimal current response ratios are 74 and 84 for 5 and 15% alcohol solutions, respectively. When the amount of PEABr decreases in the films, the conductivity of the sample in ambient alcohol with a high alcohol concentration solution increases. The alcohol was dissolved into water and carbon dioxide due to the catalyst effect of the quasi-2D (PEA)₂MA₃Sb₂Br₉ thin film. The rise and fall times for the alcohol detector were 1.85 and 0.7 s, respectively, indicating that the detector was suitable.

Properties of Halide Perovskite Photodetectors with Little Rubidium Incorporation

This study investigates the effects of Rb doping on the Rb-formamidinium-methylammonium-PbI₃ based perovskite photodetectors. Rb was incorporated in the perovskite films with different contents, and the corresponding photo-response properties were studied. Doping of few Rb (~2.5%) was found to greatly increase the grain size and the absorbance of the perovskite. However, when the Rb content was greater than 2.5%, clustering of the Rb-rich phases emerged, the band gap decreased, and additional absorption band edge was found. The excess Rb-rich phases were the main cause that degraded the performance of the photodetectors. By space charge limit current analyses, the Rb was found to passivate the defects in the perovskite, lowering the leakage current and reducing the trap densities of carriers. This fact was used to explain the increase in the detectivity. To clarify the effect of Rb, the photovoltaic properties were measured. Similarly, h perovskite with 2.5% Rb doping increased the short-circuit current, revealing the decline of the internal defects. The 2.5% Rb doped photodetector showed the best performance with responsivity of 0.28 AW⁻¹ and ~50% quantum efficiency. Detectivity as high as 4.6 × 10¹¹ Jones was obtained, owing to the improved crystallinity and reduced defects.

Technology CAD (TCAD) Simulations of Mg2Si/Si Heterojunction Photodetector Based on the Thickness Effect

Research on infrared detectors has been widely reported in the literature. For infrared detectors, PbS, InGaAs, PbSe, InSb, and HgxCd1-xTe materials are the most widely used and have been explored for photodetection applications. However, these are toxic and harmful substances which are not conducive to the sustainable development of infrared detectors and are not eco-friendly. Mg2Si is a green, healthy, and sustainable semiconductor material that has the potential to replace these toxic and damaging photoelectric materials, making photoelectric detectors (PDs) green, healthy, and sustainable. In this work, we report on the results of our simulation studies on the PN junction Mg2Si/Si heterojunction PD. A model structure of Mg2Si/Si heterojunction PD has been built. The effects of Mg2Si and Si layer thickness on the optical and electrical performance of Mg2Si/Si heterojunction PD are discussed. For the purpose of this analysis, we consider electrical performance parameters such as I-V curve, external quantum efficiency (EQE), responsivity, noise equivalent power (NEP), detectivity, on-off ratio, response time, and recovery time. The simulation results show that the Mg2Si/Si heterojunction PD shows optimum performance when the thickness of Si and Mg2Si layers are 300 nm and 280 nm, respectively. For the optimized structure, the reverse breakdown voltage was found to be -23.61 V, the forward conduction voltage was 0.51 V, the dark current was 5.58 × 10-13 A, and the EQE was 88.98%. The responsivity was found to be 0.437 A/W, the NEP was 6.38 × 10-12 WHz1/2, and the detectivity was 1.567 × 1011 Jones. With the on-off ratio of 1566, the response time was found to be 0.76 ns and the recovery time was 5.75 ns. The EQE and responsivity peak wavelength of PD show a redshift as the thickness of Mg2Si increases. The Mg2Si heterojunction PD can effectively detect infrared light in the wavelength range of 400 to 1400 nm. The simulation results can be utilized to drive the development of green Mg2Si/Si heterojunction PD in the future.