Versatile Hole Carrier Selective MoOx Contact for High Efficiency Silicon Heterojunction Solar Cells: A Review

Excellent surface passivation and carrier selective contact formed by the metal oxide induced junctions is required for future high efficiency silicon solar cells. Due to wide optical bandgap and high work function of molybdenum oxide (MoOx, x < 3) films envisioned as a superior hole selective layer in organic light emitting diodes and photovoltaics applications. We have studied the influence of ultrathin MoOx layer, as a hole-selective contact for high efficiency of silicon heterojunction (SHJ) solar cell. MoOx films can be deposited by atomic layer deposition, magnetron sputtering and thermal evaporation. Due to higher work function of MoOx films, a potential barrier can develop against electrons while it supports the hole carriers flow hence current density of SHJ solar cells can be enhanced. A summary of single layer and solar cell characteristics of MoOx layer for the application of carrier selective contact and dopant-free asymmetric heterocontact (DASH) solar cells is reported.