High Mobility Hafnium and Hydrogen Co-Doped Indium Oxide Transparent
Conductive Films and Application in High Efficiency Silicon
Heterojunction Solar Cell
Abstract
In this work, high quality hafnium and hydrogen co-doped In
2O 3 (IHfO:H) transparent conductive
films are developed via a reactive plasma deposition (RPD) technique
followed by air atmosphere annealing. Crystallinity, valence states, and
opto-electronic properties of the IHfO:H films under different H
2 concentration (0-1.5 %) and different annealing
temperature (100-250 °C) are systematically investigated. The effects of
hydrogen doping and annealing temperature on the properties of the
IHfO:H films are discussed. The high average transmittances (400-800 nm:
87.92 %; 800-2300 nm: 86.68 %), a sheet resistance of 27.53 Ω/□, and a
Hall mobility of 102.92 cm 2V −1s
−1 are achieved on the optimized IHfO:H thin film
fabricated using 0.8 % H 2 concentration with a 200 °C
annealing temperature. Finally, the IHfO:H films are applied to the
bifacial silicon heterojunction (SHJ) solar cells to serve as the
front-side transparent electrode. The significant improvement in the
long wavelength spectral response compared to the control SHJ device
with an indium tin oxide (ITO) front-side transparent electrode leads to
an increase of about 0.3 % in the efficiency and an efficiency of over
25 % is achieved on the SHJ solar cell with an IHfO:H front-side
transparent electrode.