Abstract
The thermophotovoltaic (TPV) system has been attracted as the waste heat recovery system. A TPV system consists of the heat source, the selective emitter and the TPV cells. For high conversion efficiency, it needs the wavelength matching between emitter radiation and the bandgap of TPV material. The Yb2O3 emitter is a high temperature resistant material with a selective emission spectrum. The peak wavelength of this spectrum is 980 nm. The bandgap of α- and β-In2Se3 is 1.2-1.3 eV, so that α- and β-In2Se3 are promising as the TPV material for this emitter radiation. We investigated about the crystal growth of In-Se by vapor transport method in two conditions of temperature gradients which were 0.83 and 0.33 Kmm-1. In addition, an effect on substrate which has Si-O layer on the surface was also investigated.
The hollow hexagonal cylinders with diagonal dimension of approximately 10 μm were obtained at both growth conditions. The layers with thickness of approximately 200 nm were stacked in a longitudinal direction of the hollow hexagonal cylinder. From the results of powder XRD analysis, it was revealed that these hollow hexagonal cylinders were mixed phase of In2Se3. In addition, the similar morphological crystals as hollow hexagonal cylinder were obtained onto Si-O layer.
