Reducing the optical losses and increasing the reflection while maintaining the function of doped layers at the back contact in solar cells are important issues for many photovoltaic applications. One approach is to use doped microcrystalline silicon oxide (µc-SiOx:H) with lower optical absorption in the spectral range of interest (300¿nm to 1100¿nm). To investigate the advantages, we applied the µc-SiOx:H n-layers to a-Si:H single junction solar cells. We report on the comparison between amorphous silicon (a-Si:H) single junction solar cells with either µc-SiOx:H n-layers or non-alloyed silicon n-layers. The origin of the improved performance of a-Si:H single junction solar cells with the µc-SiOx:H n-layer is identified by distinguishing the contributions because of the increased transparency and the reduced refractive index of the µc-SiOx:H material. The solar cell parameters of a-Si:H solar cells with both types of n-layers were compared in the initial state and after 1000¿h of light soaking in a series of solar cells with various absorber layer thicknesses. The measurement procedure for the determination of the solar cell performance is described in detail, and the measurement accuracy is evaluated and discussed. For an a-Si:H single junction solar cell with a µc-SiOx:H n-layer, a stabilized efficiency of 10.3% after 1000¿h light soaking is demonstrated.
|Journal||Progress in Photovoltaics: Research and Applications|
|Publication status||Published - Aug 2015|
- microcrystalline silicon oxide
- thin-film silicon solar cells
- a-Si:H solar cells
- stabilized efficiency
- measurement procedure