Hetrojunction technology based solar PV Panels are the latest solar modules which combines advantages of crystallline as well as thin film technology
The silicon heterojunction (SHJ) is one of the most attractive device structures for fabrication of high-efficiency silicon solar cells at low temperatures (<250ºC) with simple processing. The excellent surface passivation provided by H and extra band bending due to the larger band gap of aSi:H compared to c-Si makes well-designed a-Si:H emitters superior to conventional emitters made by dopant diffusion. Furthermore, a thin layer of a-Si:H, doped the same as the base wafer provides a back collector with very effective back-surface field that reduces the recombination velocity.
The current conduction through the a-Si:H collector is adequate and no localized current conduction windows are needed, in contrast to dielectric back-surface passivation layers. These outstanding properties open the path to many a-Si/c-Si heterojunction silicon solar cell designs, the most successful being the Sanyo HIT cell employing plasma enhanced chemical vapor deposition (PECVD) to deposit thin p/i (emitter) and n/i (collector) a-Si:H layers on n-type wafers.