Jia L, Zheng W, Lin R, Huang F. Ultra-high Photovoltage (2.45 V) Forming in Graphene Heterojunction via Quasi-Fermi Level Splitting Enhanced Effect.
iScience 2020;
23:100818. [PMID:
32004991 PMCID:
PMC6995729 DOI:
10.1016/j.isci.2020.100818]
[Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/19/2019] [Accepted: 01/02/2020] [Indexed: 11/05/2022] Open
Abstract
Owing to the fast response speed and low energy consumption, photovoltaic vacuum-ultraviolet (VUV) photodetectors show prominent advantages in the field of space science, high-energy physics, and electronics industry. For photovoltaic devices, it is imperative to boost their open-circuit voltage, which is the most direct indicator to measure the photoelectric conversion capability. In this report, a quasi-Fermi level splitting enhanced effect under illumination, benefiting from the variable Fermi level of graphene, is proposed to significantly increase the potential difference up to 2.45 V between the two ends of p-Gr/i-AlN/n-SiC heterojunction photovoltaic device. In addition, the highest external quantum efficiency of 56.1% (under the VUV irradiation of 172 nm) at 0 V bias and the ultra-fast photoresponse of 45 ns further demonstrate the superiority of high-open-circuit-voltage devices. The proposed device design strategy and the adopted effect provide a referential way for the construction of various photovoltaic devices.
An open-circuit voltage up to 2.45 V is achieved by the graphene heterojunction device
An efficient band assembly is designed to induce the larger quasi-Fermi level splitting
An EQE as high as 56.1% (172 nm) and a rise time as short as 45 ns are achieved
The adopted effect provides a referential way for various photovoltaic devices
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