Abstract
Zinc oxide (ZnO) is becoming an attractive semiconductor material
within optoelectronics and solar cell applications. The usage
of ZnO as a transparent conducting oxide (TCO) is interesting both as
electrode in Si-based cells and used in band gap engineered
heterojunction solar cells. Device performance can be estimated by
charge carrier simulation using commercially available software
(TCAD), but a reliable model of the transport properties of ZnO is
needed.
In the present study, ZnO-based heterostructure and Schottky contact
have been modelled and simulated for their electrical
characteristics. The ZnO model was developed and investigated through
experimental characterization of Pd Schottky contacts on ZnO using
capacitance-voltage (CV), current-voltage (IV), deep level transient
spectroscopy (DLTS) and admittance spectroscopy (ADSPEC).
A heterostructure of highly doped n-type ZnO on Si was explored for
its potential within solar cell application. In the ideal model, an
illumination using single wavelength of 2eV and a power of
2.9mW/cm^2 corresponding to AM1.5 was implemented and
the highest achieved conversion efficiency was 15.9% on p-type Si
substrate.