In-Line Post-Process Scribing for Reducing Cell to Module Efficiency Gap in Monolithic Thin Film Photovoltaics

TL;DR

This paper introduces in-line post-process laser scribing techniques to isolate parasitic shunts in monolithic thin film PV modules, significantly reducing efficiency gaps and recovering up to 50% of lost power.

Contribution

It presents novel laser scribing methods applied after module fabrication to contain shunt defects, improving overall module efficiency in thin film photovoltaics.

Findings

Up to 50% of power loss due to shunts can be recovered.

Achieves 1-2% absolute increase in module efficiency.

Demonstrates feasibility of post-process defect mitigation techniques.

Abstract

The gap between cell and module efficiency is a major challenge for all photovoltaic (PV) technologies. For monolithic thin film PV modules, a significant fraction of this gap has been attributed to parasitic shunts, and other defects, distributed across the module. In this paper, we show that it is possible to contain or isolate these shunt defects, using the state of the art laser scribing processes, after the fabrication of the series connected module is finished. We discuss three possible alternatives, and quantify the performance gains for each technique. We demonstrate that using these techniques, it is possible to recover up to 50% of the power lost to parasitic shunts, which results in 1-2% (absolute) increase in module efficiencies for typical thin film PV technologies.