Silicon heterojunction solar cells with microcrystalline emitter

Microcrystalline n-type emitters, that, compared to a-Si:H ones, ensure better electronic properties and better transparency in the visible, were used to fabricate heterojunction solar cells on crystalline silicon. The substrate surface was passivated by the deposition of a very thin intrinsic a-Si:H buffer layer. The microcrystalline n-type emitters were deposited by radio-frequency (rf) Plasma Enhanced Chemical Vapor Deposition, using a high hydrogen diluted gas mixture. The simulation of optical spectra of n/i double layers on c-Si gives a preliminary evidence that the continuity of the intrinsic a-Si:H buffer layer is preserved after the rf deposition. The photovoltaic devices incorporating microcrystalline emitters exhibit a remarkable increase of short circuit current (Jsc) and efficiency (a factor 1.24 and 1.38 respectively) compared to the case of a-Si:H emitters. Noticeable improvements are observed if the structure is applied to textured substrates.