Impact of GaAs(100) surface preparation on EQE of AZO/Al2O3/p-GaAs photovoltaic structures

Beilstein Journal of Nanotechnology

Katarzyna Gwóźdź¹  Ewa Płaczek-Popko¹  Monika Ożga²  Krzysztof Kopalko²  Jarosław Kaszewski²  Bartłomiej S. Witkowski²  Rafał Pietruszka²  Marek Godlewski²  Krystyna Lawniczak-Jablonska²  Piotr Caban²  Piotr Kuźmiuk² 

[1] Department of Quantum Technologies, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland;Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, PL-02668 Warsaw, Poland;

关键词: atomic layer deposition;    external quantum efficiency;    gallium arsenide;    photovoltaics;    surface passivation;   

DOI  :  10.3762/bjnano.12.48

来源: DOAJ

【 摘 要 】

In order to effectively utilize the photovoltaic properties of gallium arsenide, its surface/interface needs to be properly prepared. In the experiments described here we examined eight different paths of GaAs surface treatment (cleaning, etching, passivation) which resulted in different external quantum efficiency (EQE) values of the tested photovoltaic (PV) cells. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) examinations were conducted to obtain structural details of the devices. X-ray photoelectron spectroscopy (XPS) with depth profiling was used to examine interface structure and changes in the elemental content and chemical bonds. The photoluminescence (PL) properties and bandgap measurements of the deposited layers were also reported. The highest EQE value was obtained for the samples initially etched with a citric acid-based etchant and, in the last preparation step, either passivated with ammonium sulfide aqueous solution or treated with ammonium hydroxide solution with no final passivation. Subsequent I–V measurements, however, confirmed that from these samples, only the sulfur-passivated ones provided the highest current density. The tested devices were fabricated by using the ALD method.

【 授权许可】

Unknown