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III-nitride materials have attracted wide interests for optoelectronic and electronic applications due to their unique and tunable semiconducting and optical properties. Aluminum nitride (AlN) exhibits an ultra-wide bandgap of 6.2eV and wide transparency window from ultraviolet to mid-infrared, making it a promising candidate as an anti-reflective coating (ARC) material on silicon for photovoltaic (PV) devices. In this work, ray tracing is utilized to investigate the optical properties of AlN ARC on 150$\mu$m-thick c-Si absorber. AlN with thicknesses of 60–90nm are studied and the effects towards light absorption (within 300–1200nm wavelength region) and short-circuit current density ($J_{\mathrm{\text{SC}}})$ of the solar cell are analyzed. In the ray tracing, planar c-Si absorber without an ARC is used as a reference. The reference condition exhibits weighted average reflection (WAR) of 39.8% within the 300–1200nm wavelength region with $J_{\mathrm{\text{SC}}}$ of 25.49mA/cm². AlN with 80nm is found to be the optimum ARC thickness, which leads to the enhanced broadband absorption with WAR of 19.7% within the spectral region. This thickness represents the highest $J_{\mathrm{\text{SC}}}$ achieved in this work (35.71mA/cm${}^2)$.

III-nitride materials have attracted wide interests for optoelectronic and electronic applications due to their unique and tuneable semiconducting and optical properties. Gallium nitride (GaN) exhibits wide bandgap of 3.42eV, high thermal and chemical stability, with a strong potential to act as an electron selective contact (i.e., emitter) in GaN/Si heterojunction solar cells. However, despite all the advantages, to date, there is no published research that has which utilized GaN as an emitter in the GaN/Si heterojunction solar cells. In this work, SCAPS-1D simulation is utilized to investigate the electrical properties of GaN emitter on 150$\mu$m-thick monocrystalline silicon (mono c-Si) absorber layer in GaN/Si heterojunction solar cell architecture. GaN emitter with the thickness of 30–120nm are studied and the effects toward open-circuit voltage ($V_{\mathrm{\text{OC}}}$), short-circuit current density ($J_{\mathrm{\text{SC}}})$, fill factor (FF), power conversion efficiency (PCE) and external quantum efficiency (EQE) of the solar cell are analyzed. The optimum thickness of the GaN emitter is found to be 60nm with $J_{\mathrm{\text{SC}}}$ of 37.53mA/cm², $V_{\mathrm{\text{OC}}}$ of 628.73mV and PCE of 19.43%. The findings show the potential of the GaN/Si heterojunction solar cell for the future of the PV industry, especially for applications in harsh and extreme conditions.

The cubic polymorph of the binary transition metal pnictide (TMP) MnSb, c-MnSb, has been predicted to be a robust half-metallic ferromagnetic (HMF) material with minority spin gap ≳1 eV. Here, MnSb epilayers are grown by molecular beam epitaxy (MBE) on GaAs and In_0.5Ga_0.5As(111) substrates and analyzed using synchrotron radiation X-ray diffraction. We find polymorphic growth of MnSb on both substrates, where c-MnSb co-exists with the ordinary niccolite n-MnSb polymorph. The grain size of the c-MnSb is of the order of tens of nanometer on both substrates and its appearance during MBE growth is independent of the very different epitaxial strain from the GaAs (3.1%) and In_0.5Ga_0.5As (0.31%) substrates.

The D0${}_{22}$–Mn₃Ga ferrimagnet promises potential applications in spintronics due to its low magnetization, strong perpendicular magnetic anisotropy and high Curie temperature. In the form of thin and thick films, these properties are preserved. Here, we report on the structural and magnetic characterization of epitaxial D0${}_{22}$–Mn${}_{2.6}$Ga ultrathin films with thicknesses of 2nm, 5nm and 8nm grown on Cr buffer layers by magnetron sputtering. We found that the films are perfect single crystals with flat surfaces and Curie temperatures higher than 300K. The 2nm-thick ultrathin film has higher magnetization than that of the thicker films, likely due to uncompensated ferrimagnetic planes, along the c-axis, linked to the surface roughness at the atomic scale. These properties highly suit the requirements for the elaboration of spintronic devices such as magnetic tunnel junctions.