Influence of the annealing conditions on the properties of InP thin films

InP thin films were prepared on glass substrates by the spray pyrolysis technique. Results on structural, optical and electrical properties of the layers as a function of the thermal annealing are reported. XRD data indicates that samples show microstructural perfection improvement as a function of annealing time. The optical band-gap shows a dependence with the inverse of the squared crystallite size, suggesting that electron confinement has some effect. The lattice parameter and band-gap energy (BGE) of the samples annealed at 450 °C for 160 min (20-40-80-120-160-200) correspond to the reported values of InP thin films. In addition, the electrical resistivity measurement shows a slight decrease when annealing time is increased up to 80 min but it saturates annealing times between 80 and 160 min. Then it is slightly increased for larger times.