Wide bandgap p-type window layer prepared by trimethylboron doping at high temperature for a-Si:H superstrate solar cell

► Wide bandgap and compactness were both required for the window layer. ► The required window layer was prepared by TMB doping at 200-250 °C in PECVD. ► With the above window layer, the prepared solar cell VOC was higher than 900 mV.