Investigation on structural and optoelectronic properties of in-situ post growth annealed ZnSnN2 thin films

Zinc Tin Nitride (ZnSnN2) has been proposed as a new potential solar absorber for energy applications since its properties are similar to group III nitrides. But the main challenging issue for this material is to reliably synthesize films with carrier density 1017 to 1018 cm−3. In this regard, ZnSnN2 thin films were successfully developed by radio frequency (RF) magnetron sputtering and a systematic in-situ post growth annealing was performed in order to study its effect on the optoelectronic properties. At 500 °C, in-situ post growth annealed film possess good crystalline nature (69 nm) and also exhibits low carrier concentration (−3.97 and −2.42 × 1018 cm−3) and high mobility (14.5 and 11.1 cm2 V−1 s−1). The optical bandgap of the annealed ZnSnN2 film is in the range of 1.78-1.71 eV. Therefore, annealed ZnSnN2 can be regarded as potential solar absorber and alternate material for III-V nitrides.