Sub-stochiometric MoO _x by radio-frequency magnetron sputtering as hole-selective passivating contacts for silicon heterojunction solar cells

Abstract

The silicon heterojunction (SHJ) solar cell has long been considered as one of the most promising candidates for the next-generation PV market. Transition metal oxides (TMOs) shows good carrier selectivity when combined with c-Si solar cells. This has led to the rapid demonstration of the remarkable potential of TMOs (especially MoOx) with high work function to replace the p-type a-Si:H emitting layer. MoOx can induce a strong inversion layer on the interface of n-type c-Si, which is beneficial to the extraction and conduction of holes. In this paper, the radio-frequency magnetron sputtering was used to deposit MoOx films. The optical, electrical and structural properties of MoOx films are measured and analyzed, with focus on the inherent compositions and work function. Then the MoOx films are applied into SHJ solar cells. When the MoOx works as a buffer layer between ITO/p-a-Si:H interface in the reference SHJ solar cell, a conversion efficiency of 19.1% can be obtained. When the MoOx is used as a hole transport layer (HTL), the device indicates a desirable conversion efficiency of 17.5%. To the best of our knowledge, this current efficiency is the highest one for the MoOx film as HTL by RF sputtering.

Sub‐Stochiometric Nickel Oxide Hole‐Selective Contacts in Solar Cells: Comparison of Simulations and Experiments with Sputtered Films

“…[ 26,27 ] For this class of contacts, the highest efficiency of 17.5% was reported recently by Xiufang et al for sputtered MoO x . [ 28 ]…”

“…[26,27] For this class of contacts, the highest efficiency of 17.5% was reported recently by Xiufang et al for sputtered MoO x . [28] Thus, developing suitable p-type oxide hole-selective contacts is a great challenge in Si photovoltaics. Due to a variety of parameters involved, it is important to carry out numerical simulations DOI: 10.1002/pssa.202200651 Sub-stochiometric nickel oxide (NiO x ) films were investigated as a hole selective contact option in silicon (Si) heterojunction solar cells.…”

Full-Area i-a-Si:H/ATO/Mg Electron-Selective Contacts for Silicon Solar Cells

“…In this case, transition metal oxides (TMOs) came into being. TMOs have been a hot topic of photovoltaic research recently due to the fact that they are dopant-free, wide-bandgap and simple in process, which eliminates the parasitic absorption and complex semiconductor doping process. − Great progress has been made in pushing TMOs as carrier-selective contacts (CSCs), including hole-selective contacts (HSCs) such as MoO X , − WO X , − VO X , − ReO X , CuO X , NiO X , − CrO X , and ESCs such as ZnO, ,, SnO X , TiO X , ,− BaO X , MgO X , , TaO X , and so on.…”