Application of solid immersion lens to high-spatial resolution photoluminescence imaging of GaAs quantum wells at low temperatures

A solid immersion lens (SIL) was applied to microscopic photoluminescence ( PL) imaging at low temperatures. The spatial resolution corresponding to a numerical aperture of 1.0 was achieved and confirmed to be independent of t emperature from 5 to 300 K. We performed PL imaging with the SIL for a GaAs quantum well and obtained stable PL images with high- spatial resolution a t a wide temperature range from 5 to 200 K. From the temperature dependence of the PL images with high- spatial resolution, we can directly reveal the diffusion of photocarriers in the sample, which indicates the usefulness o f the SIL technique. (C) 1998 American Institute of Physics. [S0003-6951(98 )01131-0].