Investigation of Sputtered P-Type Electrical Contacts for Thin Film Cadmium Telluride-Based Solar Cells

The PV device structure has evolved significantly over the past few years and efficiencies have improved from $\sim 11\%$ to $>20\%$. While the semiconductor layers and thin film growth processes at CSU are well established and documented, the p-type electrical contact has been fabricated by painting carbon (C) and nickel (Ni) conductive paint. This introduces significant variability due to many reasons, including human factors. The presented study aims to replace this traditional electrode deposition method with a sputtered method. The effect of ambient exposure as well as variation with different thicknesses and deposition rates are also being investigated.

I. Introduction

Cadmium telluride (CdTe) thin film solar photovoltaics (PV) technology has grown increasingly popular to meet global clean energy demands. Its advantages include high manufacturing throughput, low material requirement and higher material utilization, ease of recyclability, operational reliability, low degradation rate, and one of the lowest levelized cost of energy (LCOE) [1]. While the technology is young in relation to the c-Si PV, it has already acquired about 5% of global PV market owing to it numerous advantages [2]. It continues to grow in populatiry within the energy industry. Improving the performance and reliability of this technology using scalable methods would allow greater adoption of scientific advances leading to expanding the penetration into the commercial energy market.