Quantum-confined photoluminescence from size-controlled boron doped nanocrystalline-Si:H/a-SiCx:H superlattice

•Boron-doped nanocrystalline-Si:H/a-SiCx:H superlattice was fabricated by PECVD.•Sharp well/barrier interface and relatively high density of Si QDs achieved simultaneously.•Room temperature blue photoluminescence is imputable of the quantum confinement effects.

Boron doped nanocrystalline-Si:H/a-SiCx:H (nc-Si:H/a-SiCx:H) quantum dot superlattice has been prepared by plasma enhanced chemical vapor deposition at a low temperature of 150 °C. This method for fabricating superlattice allows controlling both the size and density of Si quantum dots in potential well and the characteristics of potential barrier without subsequent annealing treatment. Cross-section high resolution transmission electron microscopy investigations confirm the periodic multi-layer structure of silicon quantum dots (~ 2 nm diameter) separated by a-SiCx:H matrix (2–3 nm thickness) with sharp interface. With strong blue photoluminescence and high perpendicular conductivity, boron doped nc-Si:H/a-SiCx:H quantum dot superlattice shows great advantages in obtaining applicable blue light emission.