Automated Contact Resistance Measurement for Solar Devices

Reliable contact resistance measurement is crucial for optimizing photovoltaic device performance. The Transmission Line Method (TLM), a four-point probe method, is often used to execute it. However, there is always some variations in the results arising from the placements of the probes by different operators. For consistent results independent of an operator, an automated measurement system integrating microcontroller-driven actuators, diagnostic tools, and a graphical interface was developed. The automated system also reduces the measurement time from 20 minutes to 3 minutes in addition reasonable repeatability mean deviations. The preliminary validated results showed accuracy discrepancies with the manual measurements which is attributed to nonuniform emitter doping, probe pressure inconsistencies, and surface irregularities. Proposed enhancements, including adaptive probes and real-time alignment feedback, aim to improve accuracy and extend applicability to advanced technologies like thin-film and heterojunction devices. This system provides a robust platform for high-throughput photovoltaic online testing and innovation in device evaluation.