1. Improved Passivation for SHJ Utilizing Dual Intrinsic a-Si:H Layers on an Inline PECVD Tool.
- Author
-
Bodlak, Lara, Temmler, Jan, Moldovan, Anamaria, and Rentsch, Jochen
- Subjects
- *
PASSIVATION , *HYDROGENATED amorphous silicon , *CHARGE carrier lifetime , *SILICON solar cells , *CHEMICAL vapor deposition , *CRYSTALLINE interfaces , *DILUTION , *EPITAXY - Abstract
Silicon heterojunction solar cells represent a key technology to approach very high conversion efficiencies. Thus, effective passivation of the interface of the crystalline silicon substrate, to reduce surface recombination losses, is essential. This is realized by controlled deposition of high quality intrinsic hydrogenated amorphous silicon (a-Si:H(i)) layers. To improve the effective minority charge carrier lifetime, epitaxial growth of the a-Si:H(i) film close to the c-Si surface must be prevented. Furthermore, stability against degradation of the passivation quality induced by application of the doped layer needs to be ensured. In the past, a severe deteriorating effect was observed after deposition of the p-doped layer. To prevent this, an innovative approach was developed by several research groups which consists of the formation of dual a-Si:H(i) layers. This describes the concept of splitting the conventional single a-Si:H(i) layer into a layer stack, each featuring different characteristics. It consist of a buffer layer at the c-Si surface with low hydrogen dilution during the deposition process, to prevent epitaxy at the a-Si:H/c-Si interface, and a high H2 dilution processed capping layer to improve the passivation quality with an increased film density, featuring less micro voids. To date, all dual a-Si:H(i) film developments found in literature are conducted on static deposition tools. To increase the throughput and lift this method on an industrial scale, here, dual a-Si:H(i) layers were processed on an inline Plasma Enhanced Chemical Vapor Deposition tool. A successful process integration of this innovative approach could be established on the MAiA platform from Meyer Burger Germany, and moreover, excellent passivation qualities could be reached with the developed dual a-Si:H(i) layers. Furthermore, a significant mitigating effect of the p-doped induced passivation degradation was achieved, which constitutes a crucial step in the investigations of stable a-Si:H(i) layers for SHJ devices. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF