The influence of the laser parameter on the electrical shunt resistance of scribed Cu(InGa)Se2 solar cells by nested circular laser scribing technique

Abstract

Laser scribing of thin film solar cells attracts increasing attention for performing integrated interconnection. For high efficiency solar modules, low damage laser scribing techniques are needed. The optimization of the laser scribing process concerns all functional properties of the device but in particular the efficiency. The recently demonstrated nested circular scribing technique allows the in-process measurement of the shunt formation due to laser scribing (P3) of the thin film solar cell. By using this technique, the influence of laser fluence and pulse overlap on the electrical shunt resistance formation at laser scribing of Cu(InGa)Se2 solar cell with ultrashort laser pulses (tp=10ps, λ=1.06μm, v=2000mm/s) was investigated. The TCO layer is removed when the laser fluence is about 0.3J/cm2. The Cu(InGa)Se2 is removed completely to expose molybdenum when the laser fluence is about 3.5J/cm2. For low defect scribing, a clear tendency of using a low pulse overlap and low laser fluences were found.