Integrated xTB and simplified Tamm–Dancoff analysis of composition-dependent electronic structure in GaInZnP/ZnSeyS1-y core/shell quantum dots with DFT and TDDFPT benchmarking

Abstract Context Alloyed core/shell quantum dots (QDs) provide a platform for composition-controlled modulation of electronic structure and optical response. Using an integrated extended tight binding (xTB) and simplified Tamm Dancoff approximation (sTDA) framework, a composition-defined GaInZnP/ZnSe y S 1-y core/shell QD series ( y = 0.00, 0.25, 0.50, 0.75, 1.00) revealed a distinctly nonlinear dependence of electronic and excited-state behaviour on shell composition. Relative stability favoure