Stable MoO_x-Based Heterocontacts for p-Type Crystalline Silicon Solar Cells Achieving 20% Efficiency

摘要

Crystalline silicon heterojunction solar cells based on hole-selective MoO(X)contacts provide obvious merits in terms of the decent passivation and carrier selectivity but face the challenge of long-term stability. With the aim to improve the performance and stability of solar cells with full area MoOX/metal contacts, a SiO(X)tunneling layer on silicon surface is intentionally formed by UV/O(3)treatment and an indium tin oxide (ITO) film is sputtered as a high-work-function electrode. Before ITO sputtering, an ultrathin V(2)O(X)capping layer is introduced to efficiently prevent MoO(X)film from air exposure and the damage by sputtering bombardment. The insertion of SiOX, V2OX, and ITO keeps the work function of MoO(X)at a high level, which improves the hole selectivity as well as the stability of the contact. Thep-Si/SiOX/MoOX/V2OX/ITO/Ag solar cell demonstrates an efficiency of 20.0% with improved stability, which is the highest value for MoO(X)heterocontacts class onp-type silicon to date.