Superior performance of V2O5 as hole selective contact over other transition metal oxides in silicon heterojunction solar cells

By O. Almora, L. G. Gerling, C. Voz, R. Alcubilla, J. Puigdollers, G. Garcia‐Belmonte. 2017

133 citations recorded by the source corpus.

Abstract Transition metal oxides (TMOs) have recently been proved to efficiently serve as hole-selective contacts in crystalline silicon (c-Si) heterojunction solar cells. In the present work, two TMO/c-Si heterojunctions are explored using MoO 3 (reference) and V 2 O 5 as an alternative candidate. It has been found that V 2 O 5 devices present larger (16% improvement) power conversion efficiency mainly due to their higher open-circuit voltage. While V 2 O 5 /c-Si devices with textured front surfaces exhibit larger short-circuit currents, it is also observed that flat solar cell architectures allow for passivation of the V 2 O 5 /n-Si interface, giving significant carrier lifetimes of 200 μ s (equivalent to a surface recombination velocity of S eff ~140 cm s −1 ) as derived from impedance analysis. As a consequence, a significant open-circuit voltage of 662 mV is achieved. It is found that, at the TMO/c-Si contact, a TMO work function enhancement Δ Φ TMO occurs during the heterojunction formation with the consequent dipole layer enlargement Δ ’= Δ + Δ Φ TMO . Our results provide new insights into the TMO/c-Si contact energetics, carrier transport across the interface and surface recombination allowing for further understanding of the nature of TMO/c-Si heterojunctions.

Subfields: Electrical and Electronic Engineering, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/95cc24add5b0aa2aacfdde2598be677625b44f40