The effect of textured surfaces on the performance of p-i-n GaAs grown on high index substrates (11N)
Publication Date : 27/10/2017
We report the effects of the surface morphology of highly doped p-i-n GaAs elaborated on high index GaAs substrates namely (111)A and (114)A, on the optical and the electrical properties. The studied samples were fabricated by Molecular beam epitaxy (MBE). The optical and electrical characterizations were investigated via photoluminescence (PL), Time-Resolved Photoluminescence (TRPL), photocurrent (PC) spectroscopy and current voltage (IV). PL measurements showed different peak emissions which are more pronounced in the PL spectra of the sample grown on (111) A. The presence of the PL peak emissions was attributed to the arsenic vacancy defects that change into pairs of Ga vacancy and Ga antisite defects when the Arsenic pressure is high. This result is attributed to the orientation dependence of the surface bonding and the kinetics of the MBE growth process. Moreover, a strong correlation between the PC measurement and carrier lifetime was observed, which is attributed to efficient photocarrier generation in the active layer of the cells. This is due to the presence of photo-generated carrier transfer from defect levels, induced by growth process, to the GaAs spacer layer. The (IV) characteristics in dark and illumination conditions show an interesting results.
No. of Downloads :