The Effects Of Doping Configuration Design On InPBi Electronic Structure

Usually,isoelectronic impurities in host ?-? materials can modify the electronic or optical properties to meet various materials and devices requirements.The incorporation of Bi into InP can further extend transition wavelengths by suppressing Auger recombination and inter-valence band absorption(IVBA)processes.In this work,InPBi materials are studied by different clusters models and bulk models,and the effects of impurity Bi atoms on the systems and different doping configurations are analyzed.The parameters of the band gap bowings with different configurations with Bi concentration are calculated.It has important reference value for determination and calibration of impurity types in the experiment.The main contents of this paper are as follows:(1)BinPm(n+m?14)cluster models.The stability,electron properties and vibration spectra of neutral BinPm clusters are calculated.The geometrical evolution of all stable structures remain amorphous as the clusters size increases.Binding energies,energy gains and HOMO-LUMO gaps confirm that all four-atom structures of BinPm clusters are more stable than others.Orbitals composition and vibrational spectra of stable clusters are analyzed.With the increase of P atomic concentration,the stability of clusters indicates that Pn clusters and tetratomic BinPm clusters are more likely to occur in InPBi compounds.(2)The InP1-xBix bulk phase models.The influence of doped Bi elements on the properties of InP1-xBix has been further studied from different dimensions,including the stress effects and chemical effects,doping concentration and doping configurations.In the case of high concentration doping,the decrease of band gaps is mainly affected by the strain effects of Bi atoms in the lattice.The impurities Bi atoms mainly perturb the valence bands near the Fermi level,and the influence on conduction band is relatively weak.With the increase of doping concentration,the band gap decreases significantly,while the spin-orbit splitting energy increases slightly.Impurities arrangements and doping ways significantly affect the alloys electronic structures.And the band properties of experiments can be viewed as a together work of these different Bi atoms arrangements.