![]() ![]() A reoptimization of these materials for this purpose was done. Finally, i a-Si:H, p a-Si:H and p μc-Si:H deposited at the UB reactor were used to develop a p- type emitter on an n-wafer. The carrier lifetimes obtained with the a-Si:H layer are more than one order of magnitude higher than those without it. This a-Si:H layer acts as physical barrier that protects the wafer from the ion bombardment in the sputtering and serves as hydrogen source that contributes to the saturation of surface defects. A very thin layer of a-Si:H was deposited over the crystalline wafer to act as intermediate layer. First, the role of sputtered alumina combined with a-Si:H in passivation was studied. Then, a-Si:H deposited at the UB was used as part of c-Si solar cells in collaboration with the UPC. The final state of the parameters of the sample does not depend on the previous history of the sample, but only on the final degradation temperature. Conversely, samples going from higher to lower temperatures experienced a sudden drop of their properties. Samples going from lower to higher temperatures experienced a recovery of their properties. The role of the temperature in seasonal effect was studied in both T-Solar cells and laboratory UB cells by degradations at different temperatures. An optimization of the intrinsic layer thickness was developed finding an optimal thickness of 200 nm. To study the light induced degradation of a-Si:H and the associated seasonal effect, a light soaking system was designed and constructed. Conversely, a-Si:H layers deposited over pm-Si:H and before μc-SiOx material caused the failure of the cell, due to a bad growth of μc-SiOx over amorphous material. a-Si:H buffer layers before the pm-Si:H intrinsic material produced an increase in the Voc due to the formation of better interface with the existing μc-SiOx doped layer. During the stage in the LPCIM, a study in polymorphous PIN and NIP solar cells was developed aiming to improve Voc. A working PIN a-Si:H solar cell fully deposited at the UB with an efficiency of 7.08% was obtained. In the complete device, the front doped layer thickness and the back reflector optimizations led to increments on the short circuit current of 11% and 12% respectively, and improvements in other parameters. SILICIO TIPO P SERIESFor p μc-Si:H, after four optimization series (temperature, TMB flow, power and SiH4 flow) device quality material was also obtained (σdark=1.32 S/cm, Eg=2.07 eV, Φ=0.596). The series developed for p a- Si:H (TMB flow, temperature, pressure and CH4 flow) led to obtaining device quality material (σdark=1.1♱0-5 S/cm, Ea=0.43 eV, Eg=2.02 eV). The optimum layer was obtained at low depletion values, with a hydrogen flow ratio of 2:1 and at 200✬. Intrinsic a-Si:H as active layer was optimized with series in three parameters: Depletion, hydrogen flow and temperature. Optimization of intrinsic and doped a-Si:H was developed based on several optical and electrical properties. ![]() The main objective of this work is to study and optimize the amorphous silicon deposited in a PECVD reactor of recent acquisition, making it suitable for thin film and c-Si based solar cells. Optimization of hydrogenated amorphous silicon for its use in different photovoltaic technologies Please use this identifier to cite or link to this item: ![]()
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