Photovoltaic & Optoelectronic Device Group

Research group

Research theme

About

Related research groups

Silver-Bismuth Bilayer Anode for Perovskite Nanocrystal Light-Emitting Devices.

The journal of physical chemistry letters 11:10 (2020) 3853-3859

Authors:

Xinyu Shen, Xiang Zhang, Chengyuan Tang, Xiangtong Zhang, Po Lu, Zhifeng Shi, Wenfa Xie, William W Yu, Yu Zhang

Abstract:

Perovskite nanocrystal light-emitting devices (PNC LEDs) exhibit great potential in display and lighting applications. Balanced hole and electron injection in the light-emitting layer is undoubtedly an effective way to improve LED performance. Here, bismuth (Bi) was introduced into PNC LEDs to form a silver-bismuth (Ag-Bi) bilayer anode. Ag diffused into a defective 2 nm thick Bi layer to form an alloy-like state that promoted hole injection, reduced the charge transfer resistance, and enhanced charge transfer, leading to more balanced hole-electron carriers in the emission layer through hole injection enhancement. As a result, the turn-on voltage and brightness changed from 2.41 V and 2200 cd m-2, respectively, for CsPb1-xZnxI3-based LEDs with a Ag monolayer anode to 2.2 V and 3714 cd m-2, respectively, for devices with a Ag-Bi bilayer anode. In addition, the performance of CsPbI3 and CsPbBrI2 PNC-based LEDs has also been effectively improved by using a Ag-Bi bilayer anode.

Thermal stability of CH3NH3PbIxCl3-x versus [HC(NH2)2]0.83Cs0.17PbI2.7Br0.3 perovskite films by X-ray photoelectron spectroscopy

Applied Surface Science Elsevier 513 (2020) 145596

Authors:

Ma艂gorzata Kot, Mykhailo Vorokhta, Zhiping Wang, Henry J Snaith, Dieter Schmei脽er, Jan Ingo Flege

Light soaking in metal halide perovskites studied via steady-state microwave conductivity

Communications Physics Springer Nature 3:1 (2020) 73

Authors:

C Lowell Watts, Lee Aspitarte, Yen-Hung Lin, Wen Li, Radwan Elzein, Rafik Addou, Min Ji Hong, Gregory S Herman, Henry J Snaith, John G Labram

Towards unification of perovskite stability and photovoltaic performance assessment

(2020)

Authors:

Bernard Wenger, Henry J Snaith, Isabel H S枚rensen, Johannes Ripperger, Samrana Kazim, Shahzada Ahmad, Edgar R Nandayapa, Christine Boeffel, Silvia Colodrero, Miguel Anaya, Samuel D Stranks, Iv谩n Mora-Ser贸, Terry Chien-Jen Yang, Matthias Br盲uninger, Thorsten Rissom, Tom Aernouts, Maria Hadjipanayi, Vasiliki Paraskeva, George E Georghiou, Alison B Walker, Arnaud Walter, Sylvain Nicolay

Charge-carrier trapping dynamics in bismuth-doped thin films of MAPbBr3 perovskite

Journal of Physical Chemistry Letters American Chemical Society 11:9 (2020) 3681-3688

Authors:

Aleksander M Ulatowski, Adam D Wright, Bernard Wenger, Leonardo RV Buizza, Silvia G Motti, Hannah J Eggimann, Kimberley J Savill, Juliane Borchert, Henry J Snaith, Michael B Johnston, Laura M Herz

Abstract:

Successful chemical doping of metal halide perovskites with small amounts of heterovalent metals has attracted recent research attention because of its potential to improve long-term material stability and tune absorption spectra. However, some additives have been observed to impact negatively on optoelectronic properties, highlighting the importance of understanding charge-carrier behavior in doped metal halide perovskites. Here, we present an investigation of charge-carrier trapping and conduction in films of MAPbBr3 perovskite chemically doped with bismuth. We find that the addition of bismuth has no effect on either the band gap or exciton binding energy of the MAPbBr3 host. However, we observe a substantial enhancement of electron-trapping defects upon bismuth doping, which results in an ultrafast charge-carrier decay component, enhanced infrared emission, and a notable decrease of charge-carrier mobility. We propose that such defects arise from the current approach to Bi-doping through addition of BiBr3, which may enhance the presence of bromide interstitials.