Bondability of ultrasonic Aluminum bonds on the molybdenum (de)selenide and molybdenum of back contact layer of copper indium gallium (de)selenide CIGS thin film photovoltaic solar panel

Abstract

This paper aims to study the bondability of ultrasonic Aluminum, Al bonds on Mo and MoSe2 layers of back-contact metal of copper indium gallium (de)selenide (CIGS) thin film photovoltaic (TFPV) solar panel. The bondability of ultrasonic Al bonds were evaluated based on the contact resistance, Rc, peel strength and electrical characteristics measured using transmission line method (TLM), peel test, and current–voltage (I-V) measurement, respectively. Besides, the qualitative results of load-distance profiles from tensile test also have been used to evaluate the bondability of the ultrasonic Al bonds. Two type of lamination constructions namely construction 1 and construction 2 were built on the CIGS TPFV solar panel with ultrasonic Al bonds on Mo and MoSe2. It was noted that the new method of removing CIGS layer up until MoSe2 is the plausible technique to be used. Ultrasonic Al bond on Mo layer has higher bondability as compared to that of ultrasonic Al bond on MoSe2 through the quantitative results of Rc, peel strength and qualitative result of load-distance profile. CIGS TFPV solar panel with construction 2 is the suitable construction for the CIGS TFPV solar panel due to the higher rigidity, and even stress distribution experienced during lamination process as compared to that of construction 1. It is noted that steps taken from ultrasonic bonding until lamination process has increased the cumulative contact area and decreased the Rc and consequently increased the efficiency of CIGS TFPV solar panel with ultrasonic Al bond on MoSe2 layer.