A Physical Model for Non-ohmic Shunt Conduction and Metastability in Amorphous Silicon p-i-n Solar Cells

Sourabh Dongaonkar, Purdue University - Main Campus
Karthik Y, Indian Institute of Technology - Bombay
Souvik Mahapatra, Indian Institute of Technology - Bombay
Muhammad A. Alam, Network for Computational Nanotechnoloy, Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University

Date of this Version



37th IEEE Photovoltaic Specialists Conference, 2011


We present a physical model of non-ohmic shunt current in a-Si:H p-i-n solar cells, and validate it with detailed measurements. This model is based on space-charge-limited (SCL) transport through localized p-i-p shunt paths, which can arise from contact metal incorporation in a-Si:H layer. This model explains both the electrical characteristics and the metastable switching behavior of the shunts within an integrated framework. We first verify the SCL model using simulations and statistically robust measurements, and then use this picture to analyze our systematic observations of non-volatile switching in these shunts. Our work not only resolves broad experimental observations on shunt behavior, but also suggests possible techniques for alleviating shunt induced performance and reliability issues.


Electronic Devices and Semiconductor Manufacturing