1 research outputs found
Hole Selective MoO<sub><i>x</i></sub> Contact for Silicon Solar Cells
Using
an ultrathin (∼15 nm in thickness) molybdenum oxide
(MoO<sub><i>x</i></sub>, <i>x</i> < 3) layer
as a transparent hole selective contact to n-type silicon, we demonstrate
a room-temperature processed oxide/silicon solar cell with a power
conversion efficiency of 14.3%. While MoO<sub><i>x</i></sub> is commonly considered to be a semiconductor with a band gap of
3.3 eV, from X-ray photoelectron spectroscopy we show that MoO<sub><i>x</i></sub> may be considered to behave as a high workfunction
metal with a low density of states at the Fermi level originating
from the tail of an oxygen vacancy derived defect band located inside
the band gap. Specifically, in the absence of carbon contamination,
we measure a work function potential of ∼6.6 eV, which is significantly
higher than that of all elemental metals. Our results on the archetypical
semiconductor silicon demonstrate the use of nm-thick transition metal
oxides as a simple and versatile pathway for <i>dopant-free</i> contacts to inorganic semiconductors. This work has important implications
toward enabling a novel class of junctionless devices with applications
for solar cells, light-emitting diodes, photodetectors, and transistors