Fioretti, Angela N.Chang Chien, Tzu-ChinXiao, YashiBallif, ChristopheBoccard, Mathieu2019-07-032019-07-032019-07-03201910.1109/PVSC40753.2019.8980621https://infoscience.epfl.ch/handle/20.500.14299/158759Carrier-selective, passivating contacts have allowed silicon heterojunction (SHJ) cells to reach recordbreaking efficiencies particularly in all-back-contacted designs. However, two-side-contacted SHJ cell efficiency has been limited due in part to parasitic absorption losses up to 3 mA/cm2 in the aSi:H layers. More transparent materials could reduce this current loss while minimizing process complexity. Gallium nitride (GaN), with a bandgap of 3.4 eV and an advantageous band alignment with silicon, could be applied as a transparent electron-selective layer. Here, we report on SHJ solar cells utilizing PECVD GaN layers grown at 200°C as electron-selective contact. First devices exhibited open-circuit voltages of ~575 mV due to poor passivation, and low conductivity of the as-yet undoped GaN layers induced high series resistance (Rs). However, this Voc suggests the potential for electron selectivity if appropriate passivation and doping strategies are implemented.photovoltaic cellsheterojunctionspassivating contactsnitridestext::conference output::conference proceedings::conference paper