[20p-S321-1~16] 3.13 Semiconductor optical devices

▲ [20p-S321-4] Enhanced Brightness from Ge Nanostructures Sensitized by CdTe/PbS QDs

〇(P)Satish Laxman Shinde¹, Li-Wei Nein¹, S. Ishii¹, T. Nagao¹ (1.NIMS)

Keywords:Semiconductor, phosphor, Brightness

Due to the fascinating optical and electronic properties and high thermal stability, Ge and GeO2 has been considered as a promising material for optoelectronic applications.1-2 Here, we have demonstrate enhanced brightness from Ge nanostructures when sensitized with low band gap CdTe/PbS quantum dots. Controlling the shapes and defects levels in the Ge/GeO2, the photoluminescence (PL) properties can be tuned. For the pyramids shape Ge nanostructures, it is observed that PL is mainly from tip region due the high Ge/GeO2 interfacial defects density. The PL from various Ge nanostructures can be enhance by sensitizing low band gap CdTe/PbS QDs. The detailed investigations of surface defects for enhanced brightness carried out by PL imaging. Interestingly, defects containing wide band gap GeO2 act as acceptors, while low band gap PbS quantum dots act as donors for the charge/energy transfer. One of the major implications is the designing of broad-weak-luminescent wide and narrow band gap materials as bright white light emitting phosphors that convert the ultraviolet into visible light efficiently.

References:
1. Zhou, M.; Shao, L.; Miao, L. J. Phys. Chem. A 2002, 106, 6483.
2. Shinde, S. L.; Nanda, K. K. CrystEngComm 2013, 15, 4049.