GROWTH OF GASB ON GAAS ALAS MIRRORS FOR 1.68 MU-M DETECTORS/

Distributed Bragg reflector mirrors (grown by MBE) are designed to giv e maximum reflectance at 1.68 mu m. The DBR is incorporated into a res onant cavity enhanced (RCE) detector by growing GaSb (by MOVPE) on top of the minor. Device results show such an RCE detector has enhanced q uantum efficiency and photocurrent compared to a nonresonant detector grown at the same time. The initial nucleation and growth of GaSb on G aAs by MOVPE is studied by atomic force microscopy (AFM). Conditions a re established for the nucleation of small islands of GaSb using TMGa and TMSb as precursors. However, the dark current suggests that the in itial nucleation of GaSb is still not optimised. in order to nucleate smaller GaSb islands at lower temperatures, two new precursors are use d. Triisopropylgallium (TIPGa) and trisdimethylaminoantimony (tDMASb) are used in combination for the first time to grow GaSb at 480 degrees C. This results in nucleation of much smaller islands and subsequent improvement in the dark current and quantum efficiency of the nonreson ant detector. Further work is needed on the equivalent (RCE) detector.