Design, fabrication and testing of silicon interdigitated back contact (IBC) solar cells.

摘要

he Interdigitated Back Contact (IBC) solar cell relocates the classical cell's front p-n junction to its rear surface. In this manner, the device's optical and electrical characteristics are decoupled, thereby allowing their separate optimization. This thesis describes the work done in implementing a process sequence for IBC solar cell fabrication at Concordia's Microelectronics Laboratory.;In anticipation of the IBC design's more stringent infrastructure and process requirements, modifications were first made to the cleanroom facilities and to the silicon processing technology. Changes made to the latter included the adoption of more effective wafer cleaning, photolithography and p-n junction-formation procedures. A 4-mask IBC process sequence was subsequently developed which included Van der Pauw, Contact Resistance and Contact String test structures in its design to facilitate post-process testing procedures.;The sequence yielded devices with (dark) reverse saturation currents on the order of 2 nA, fill factors ranging from 72% to 74%, series resistances of approximately 8 ohms and efficiencies of 1% (AM2 spectrum). Photoconductive decay measurements revealed that the devices' photogenerated minority carriers had effective lifetimes of about 55