Evaluation of the chemical, electronic and optoelectronic properties of γ-CuCl thin films and their fabrication on Si substrates
Citation:
Lucas, F. O., Mitra, A., McNally, P.J., Daniels, S., Bradley, A.L., Taylor, D.M., Proskuryakov, Y.Y., Durose, K., Cameron, D.C., Evaluation of the chemical, electronic and optoelectronic properties of γ-CuCl thin films and their fabrication on Si substrates, Journal of Physics D: Applied Physics, 2007, 40, 11, 3461 - 3467Download Item:
Abstract:
CuCl is a I–VII semiconductor material with a direct band gap of ~3.4 eV. It exhibits a zincblende structure (γ-phase) at low temperatures, up to ~680 K. Unlike GaN, ZnO and related materials, CuCl has a relatively low lattice mismatch with Si (<0.4%) and a large excitonic binding energy (~190 meV). This suggests the possibility of the fabrication of excitonic-based blue/UV optoelectronic devices on Si with relatively low threading dislocation densities. In this study, CuCl has been deposited and examined as a candidate material for the fabrication of these devices. X-ray diffraction (XRD) measurements confirmed that the deposited films were preferentially oriented in the (1 1 1) plane. Room temperature photoluminescence measurements reveal a strong Z3 free exciton peak (3.232 eV). Both steady state dc and ac impedance spectroscopy experiments suggested that the deposited CuCl is a mixed ionic–electronic semiconductor material. An electronic conductivity of the order of 2.3 × 10−7 S cm−1 was deduced to be in coexistence with Cu+ ionic conductivity using irreversible electrodes (Au), while a total conductivity of the order of 6.5 × 10−7 S cm−1 was obtained using reversible electrodes (Cu) at room temperature. Further to this, we have identified some of the challenges in fabricating an optoelectronic device based on a CuCl/Si hybrid platform and propose some possible solutions.
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http://people.tcd.ie/bradlelDescription:
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Author: Bradley, Louise
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Journal of Physics D-Applied Physics;40;
11;
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Optoelectronic deviceDOI:
http://dx.doi.org/10.1088/0022-3727/40/11/030Metadata
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