Journal Article

ALD Grown Al2O3 as Interfacial Layer in ITO Based SIS Solar Cells

Gangopadhyay, U, Chowdhury, K, Mandal, R

2021

Overview

Conventional diffusion process to form the emitter of a c-Si solar cell is a complicated process with high thermal as well as economic budget. An alternative to avoid this process is to form MIS/SIS structured solar cells, where different process is used to form the emitter portion of the cell. In this study, 3 × 3 (ITO-Al2O3-n-Si) structured SIS cell is developed, where n-Si is the base material, Al2O3 and ITO layer act as hole selective layer and emitter layer, respectively. Sputtered ITO layer of thickness 150 nm acts as a degenerative semiconductor as well as ARC. For ITO coated cell, average reflectance reduced to 4.54 % from 13.63% compared with only textured cell. Metallization is done using Ag on both the sides on the front side above the ITO layer and a continuous contact on the back side by vacuum coating unit. Apart from hole tunnelling, ALD grown very thin 1.5 nm layer of Al2O3 acts as a passivation layer and increases minority carrier lifetime from 9.732 S to 17.548 S. Achieved open circuit voltage (Voc) and short circuit current (Isc) are 684 mV and 35 mA, respectively.

• Publisher: Sumy State University, Journal of Nano - and Electronic Physics
• Subject: Aluminum oxide / Atomic layer epitaxy / Carrier lifetime / Circuits / Diffusion layers / Emitters / Metallizing / Minority carriers / Open circuit voltage / Photovoltaic cells / Short circuit currents / Solar cells / Thickness