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

Authors K. Chowdhury1,2, U. Gangopadhyay3, R. Mandal2

1Department of Renewable Energy, Maulana Abul Kalam Azad University of Technology, West Bengal, India

2School of Energy Studies, Jadavpur University, Kolkata, India

3CARREST, Meghnad Saha Institute of Technology, Kolkata, India


Issue Volume 13, Year 2021, Number 3
Dates Received 10 January 2021; revised manuscript received 15 June 2021; published online 25 June 2021
Citation K. Chowdhury, U. Gangopadhyay, R. Mandal, J. Nano- Electron. Phys. 13 No 3, 03004 (2021)
PACS Number(s) 84.60.Jt
Keywords SIS (123) , ITO (13) , Al2O3 (6) , Reflectivity (3) , Degenerative semiconductor, Hole selective contacts.

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.

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