Comparative Analysis of Laser Generated P2 Processes for a-Si:H Modules and their Electrical Influence on the Final Device

In this work we study the contact resistance introduced through the P2 laser patterning of a-Si:H PV. The process is evaluated for different transparent conductive oxides (TCO) of interest and significant irradiation condition. In particular we study the ablation process for the a-Si structure deposited in AZO and SnO2. Backscribing and direct writing configuration for ns and ps pulse duration, using visible wavelengths (532nm) and UV (355nm) were investigated. A comparison of the contact resistance Rc and the open circuit resistance Roc for different scribing procedures is presented. The results obtained from the morphological and electrical studies of the P2 scribes are used to assess the quality of the formed contact. Non- optimized scribes can lead to very low quality contacts with the formation of Schottky barriers or non-ohmic contacts leading to final devices presenting anomalous JV characteristic and low fill factors.