Electron-Selective Scandium-Tunnel Oxide Passivated Contact for n-Type Silicon Solar Cells

Dopant-free carrier-selective contacts have a high potential for cost reduction in solar panel production because of the simple structure and manufacturing procedure. Increasing the carrier selectivity is critical for improving the efficiency of heterostructure solar cells. Low work function metals have been explored as electron-selective contact (ESC) recently. In this paper, a high-performance silicon-oxide/scandium (SiOx/Sc) ESC structure is explored as an ESC that exhibits a good contact and surface passivation. The lowest contact resistivity of 23mcm(2) and the champion single-surface saturated dark current density (J(oe)) of 61fAcm(-2) have been achieved with a full-area SiOx/Sc passivated contact. It was revealed that the ScOx formed by the reaction of Sc and SiOx was the critical material modifying the interfacial work function. Finally, the champion efficiency of >15% and an open circuit voltage (V-oc) of >620mV are achieved for the full-area rear SiOx/Sc passivated-contact n-type c-Si solar cell. A comprehensive analysis indicates that a high-efficiency n-type solar cell with efficiency of >20% is expected with the application of high-efficiency structures.