Defect induced ambipolar conductivity in wide-bandgap semiconductor SrS: Theoretical perspectives

Due to the absence of high-performance ambipolar wide-bandgap (WBG) semiconductors, the realization of active transparent photoelectronic devices is precluded. Herein, based on the hybrid functional calculations, we predict that, in a wide-bandgap semiconductor strontium sulfide (SrS), the Br (Rb) substituting S (Sr) is an ideal n (p)-type defect. SrBr2 and Rb2S are promising dopant sources for introducing Br and Rb, respectively. Moreover, the Sr-rich (Sr-poor) condition is the optimum growth environment to fabricate the Br-S (Rb-Sr) defects. Thermodynamic equilibrium simulations indicate that the concentration of Br-S and Rb-Sr can exceed 4 x 10(19) cm(-3) at high growth temperatures. After rapid quenching from the growth temperature to room temperature, the free carrier densities can reach 1.56 x 10(19) cm(-3) for electrons and 1.02 x 10(18) cm(-3) for holes. These results show SrS is a promising ambipolar WBG semiconductor that has huge potential applications in future optoelectronic devices. Published under an exclusive license by AIP Publishing.