Non‐Traditional Positively‐Biased Narrow‐Band Perovskite Single‐Crystal Photodetectors Enabled by Interfacial Engineering

Journal Article · 05 January 2022 · Advanced Optical Materials

DOI: https://doi.org/10.1002/adom.202102225 · OSTI ID:1838407

Li, Junchi  ^[1]; Chen, Yifu ^[2]; Zhang, Bin ^[1]; Li, Jia ^[1]; Uddin, Zaheen ^[1]; Jiang, Xinan ^[3]; Wang, Xueyun ^[3]; Hong, Jiawang ^[3]; Yuan, Yongbo ^[2]; Stathatos, Elias ^[4]; Xiao, Hanning ^[1]; Pan, Anlian ^[1]; Liu, Yi ^[5]; Yang, Bin  ^[1]

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1. College of Materials Science and Engineering Hunan University Changsha Hunan 410082 China
2. Hunan Key Laboratory of Super Microstructure and Ultrafast Process School of Physics and Electronics Central South University Changsha Hunan 410083 China
3. Department of Applied Mechanics Beijing Institute of Technology Beijing 100081 China
4. Department of Electrical and Computer Engineering University of the Peloponnese Patras 26334 Greece
5. The Molecular Foundry Lawrence Berkeley National Laboratory Berkeley California 94720 USA

Abstract The positive bias in theory narrows down the depletion region and thus results in significant charge injection, which should be detrimental to charge generation and collection performance for traditional photodetectors. Here, instead, it is found that the external quantum efficiency (EQE) is increased by more than 50 times when the photodetector is positively biased. A positive bias of +6 V drives ion migration of Br ⁻ and Cs ⁺ towards the anode and cathode, respectively, leading to self‐doping within bulk single crystals to form an advantageous p‐i‐n junction for better charge collection in the devices. Meanwhile, the injected holes are allowed to tunnel through the cesium lead bromide/fullerene interface to reach the cathode which also significantly contributes to the enhancement of EQE in the forward‐biased devices. The positively‐biased narrow‐band (full width at half maxima (FWHM) = 16 nm) photodetectors exhibit a specific detectivity of 6.5 × 10 ¹⁰  Jones at 550 nm, along with the −3 dB cutoff frequency of 2776 Hz. By manipulating charge injection and ion migration using interfacial engineering, a class of non‐traditional, positively‐biased, and highly narrow‐band photodetectors is demonstrated, which offers an alternative design strategy for imaging, biosensing, automatic control, and optical communication.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1838407
• Journal Information: Advanced Optical Materials, Journal Name: Advanced Optical Materials Journal Issue: 5 Vol. 10; ISSN 2195-1071
• Publisher: Wiley Blackwell (John Wiley & Sons)Copyright Statement
• Country of Publication: Germany
• Language: English