High-efficiency thin-film silicon solar cells realized by integrating stable a-Si:H absorbers into improved device design

We report that thin-film silicon solar cells exhibiting high stabilized efficiencies can be obtained by depositing hydrogenated amorphous silicon (a-Si:H) absorbers using triode-type plasma-enhanced chemical vapor deposition. The improved light-soaking stability and performance of solar cells are also realized by optimizing the device design, such as p and p-i buffer layers. As a result, we attain independently confirmed stabilized efficiencies of 10.1-10.2% for a-Si:H single-junction solar cells (absorber thickness: t(i) = 220-310 nm) and 12.69% for an a-Si:H (t(i) = 350 nm)/hydrogenated microcrystalline silicon (mu c-Si:H) tandem solar cell fabricated using textured SnO2 and ZnO substrates, respectively. The relative efficiency degradations of these solar cells are similar to 10 and 3%, respectively, under 1 sun illumination at 50 degrees C for 1000 h. (C) 2015 The Japan Society of Applied Physics