Three-primary-color photoluminescence from CdS/Si nanoheterostructure grown on silicon nanoporous pillar array

CdS/Si nanoheterostructure was prepared by growing CdS nanocrystallites (nc-CdS) onto silicon nanoporous pillar array (Si-NPA) via a heterogeneous reaction process. The pillars of CdS/Si-NPA were constructed by an outermost shell of nc-CdS membrane, an innermost core of nanoporous silicon pillar, and an interface with nc-CdS embedded into amorphous SiO2 matrix. Blue, green, and red emissions were observed in CdS/Si-NPA and the origins were attributed to the emission from Si-NPA, the band edge transition, and the surface states of sulphur vacancies of nc-CdS, respectively. The three-primary-color photoluminescence realized in CdS/Si-NPA might be applied in solid state lighting. (c) 2007 American Institute of Physics.