High-performance HIT solar cells for thinner silicon wafers

Novel heterojunction solar cells with conversion efficiencies approaching 21% on p-type crystalline silicon substrates

“…The main improvement (which is in the fill-factor) was achieved by optimizing the back PECVD stack. It is noteworthy that the IQE of the HJ-ELITE cells matches the spectral response of the highest efficiency HJ solar cells reported by Sanyo on n-type c-Si substrates [1] (Fig. 13).…”

“…Although high-efficiency HJ solar cells have been demonstrated on n-type c-Si using PECVD (23.0% in the lab and 21.1% in production [1]), HJ solar cell efficiencies reported on p-type c-Si have been limited to 17.4% using PECVD [2], and 19.3% using hot-wire CVD [3] (which is challenging to scale up). The development of high-efficiency HJ solar cells on p-type Si opens many industrial options by allowing the usage of widely available p-type Si substrates…”

Recent Advances in and New Perspectives on Crystalline Silicon Solar Cells with Carrier-Selective Passivation Contacts

“…In recent years, the benefits of the asymmetric heterocontact concept have been realized, perhaps most famously by the silicon heterojunction cell architecture (SHJ, sometimes called HIT) [19][20][21][26][27][28], which has now overtaken its homojunction counterpart in terms of efficiency. Besides SHJ solar cells, the recently emerging tunnel oxide passivated contact (TOPCon) [22,23], polysilicon on oxide (POLO) junction [24,25], and passivated emitter and rear poly-silicon (PERpoly) [29] solar cells also employ carrier-selective passivation contacts by stacking doped-silicon films, either amorphous or polycrystalline.…”

“…Since the 1980s, Sanyo Corporation, which was subsequently acquired by Panasonic Corporation, has been in the leading position in the SHJ solar cell industry. The first a-Si:H/c-Si heterojunction solar cell was fabricated in 1983 [26][27][28]. The potential of heterojunction technology was demonstrated by Sanyo in 1992, with an intrinsic a-Si:H ultra-thin buffer layer between a doped emitter and c-Si wafer to reduce the interface state density, decrease surface recombination, and lower emitter saturation current, which was named HIT [26][27][28].…”

“…The first a-Si:H/c-Si heterojunction solar cell was fabricated in 1983 [26][27][28]. The potential of heterojunction technology was demonstrated by Sanyo in 1992, with an intrinsic a-Si:H ultra-thin buffer layer between a doped emitter and c-Si wafer to reduce the interface state density, decrease surface recombination, and lower emitter saturation current, which was named HIT [26][27][28]. In SHJ solar cells, the emitter and back surface field are formed by doped a-Si:H films, sandwiching the c-Si wafer, among which an intrinsic a-Si:H buffer layer of a few nanometers in thickness is typically inserted between the c-Si surface and the doped a-Si:H films to further improve the passivation.…”