Non‐Radiative Recombination Dominates Voltage Losses in Cu(In,Ga)Se ₂ Solar Cells Fabricated Using Different Methods

Voltage losses reduce the photovoltaic conversion efficiency of thin-film solar cells and are a primary limitation in Cu(In,Ga)Se2. Herein, voltage loss analysis Cu(In,Ga)Se2 fabricated at three institutions with variation process, bandgap, absorber structure, postdeposition treatment (PDT), is presented. Nonradiative due to Shockley–Read–Hall charge carrier recombination dominate constitute >75% total compared <25% from radiative losses. The results nonideal absorption carriers band tails that stem local composition-driven potential fluctuations. It shown significant bulk lifetime improvements achieved for all alkali PDT processed absorbers, chiefly associated reductions nonradiative recombination. Primary contributions (radiative nonradiative) change little across fabrication processes, but submechanisms (bulk lifetime, net acceptor concentration, interface recombination) differentiate pathways this series cells.