Roles of microcrystalline silicon p layer as seed, window, and doping layers for microcrystalline silicon p-i-n solar cells

The roles of the hydrogenated microcrystalline silicon (μc-Si:H) p layer in the μc-Si:H p-i-n solar cell fabricated by plasma-enhanced vapor deposition are determined through evaluation of the photovoltaic characteristics of solar cells fabricated by varying the deposition time of p layer. Mechanisms of p-layer growth are analyzed with in situ Auger electron spectroscopy and ex situ Raman scattering spectroscopy. Each successive regime of film growth including an amorphous silicon layer, an incubation layer containing crystalline silicon nuclei, and a layer filled with conical crystalline silicon grains that evolves in the p-layer process leads to diverse changes in the crystalline development of the subsequent μc-Si:H i layer and in the characteristics of the solar cell.