Abstract
The shallow acceptor characteristics of calcium in GaAs were investigated by photoluminescence spectroscopy and Hall measurement. Calcium impurity was introduced into GaAs substrate by ion-implantation. The Ca concentration was ranged from 3×10 16 to 1×10 20 cm -3 . In 2K PL spectra, a transition from conduction band to shallow Ca acceptor (e, Ca) was found at ∼1.491eV. A binding energy of 28.4meV for Ca was obtained. The emission g C a , which is usually strongly related to shallow impurity like C in GaAs, presents in all Ca + implanted GaAs samples and its intensity increases with increasing Ca concentration, confirming that Ca is a shallow impurity in GaAs. Temperature dependence PL spectra showed that 1.491eV band in Ca + ion-implanted GaAs exists at temperature as high as 40K while in virgin GaAs, the 1.491eV band quenches at temperature below 20K, supporting our (e, Ca) assignment. Hall measurement revealed that all the samples are p-type conduction and the maximum sheet hole concentration is 4×10 12 cm -2 . All the results indicate that Ca is a shallow acceptor impurity in GaAs.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
