In this article, the performance analysis of recessed gate and field-plated III-nitride Nano-HEMT (High Electron Mobility Transistor) developed on β-Ga 2O 3 substrate with and without AlN spacer layer is studied. The two-dimensional electron gas (2DEG) formed at the AlGaN/GaN interface is crucial in changing the characteristics of AlGaN/GaN HEMTs. The different transport, DC, and AC characteristics of the proposed III-nitride HEMT with spacer layer are numerically simulated and compared with the HEMT without spacer layer. The major findings of this research demonstrate that the AlN spacer layers large band off set, strong polarisation field, and high barrier allow the increased concentration of 2DEG, when it is introduced between AlGaN/GaN interface. Furthermore, the AlN layer moves the 2DEG distribution shifts from the surface, which diminishes interface scattering. Further, AlN thickness variation influences the polarisation field and conduction band offset, which impacts the concentration and mobility of 2DEG.

CZTS material is seen as a very potential replacement for toxic CIGS, and CIS material as a thin-film solar cell absorber layer. Because of its extraordinary light absorption capacity and generation of electron-hole pairs, CZTS has been implemented as a thin-film solar cell. Research is going on over the last decade on increasing the efficiency of the CZTS solar cell. Different structural and material properties have been experimentally altered to achieve higher efficiency. But even after several attempts the single junction CZTS solar cell has not achieved an efficiency of more than 13%. In this article, a detailed review is done of the developments that have taken place and the future scope of the CZTS thin-film solar cell (TFSC). From its evolution, materials preparation, fabrication process, TFSC design, and defects in CZTS to its implementation as a solar cell are discussed in this manuscript.