Optical properties of GaAs films deposited via pulsed ion ablation

Transport charge of gallium arsenide films synthesized on polycrystalline silicon by ion ablation

“…At maxima ,  ph , K at T ann =350-450, К and   approaches maximum   -eV, while LS maximum density is N(E F )=(3-4)•10 18 eV -1 cm -3 which indicates the increase in contribution of  h (figures 1-3). The relaxation of nonequilibrium charge carriers and their recombination between shallow LS and deep levels with >1.4 eV defects take place, which is confirmed by spectra K(hT ann ) [11][12][13]. At T ann =450-600 К the correlation between the decrease in   ph , the increase in K and    the decrease in N(E F )=4•10 18 to 6•10 16 eV -1 cm -3 is observed, which indicates the increase in contribution to the activation mechanism electromigration (figures 1-3).…”

“…N-type of  and  ph predominate in GaAs/Si, whereas, the concentration of LS donors is higher in comparison with the one of acceptors. The effect of donors increases in the films deposited on the periphery [11,12]. In the centre of deposition, defect contribution increases with their possessing shallow acceptor LS with energy =E v +(0.05-0.16) eV, where E v is a valence band (VB) top.…”

“…Vacuum annealing modifies the electronic state of film materials in consequence of its partial crystallization, the change in the defect charge state and the formation of defect complexes [5,7,8,[11][12][13]15]. LS density near the film surface and on the boundary with substrate changes, arsenic clusters form [4,8,12].…”

“…As K(U) show, the effect of light-generated holes in VB on  ph (T, U) increases. The properties are affected by the defect annealing and recharging, as well as the dissociation of unstable complexes [11,13]. The dependences N(E F )( 0 ,   ) indicate less disordering of GaAs/Si films by defects in comparison with GaAs/Al 2 O 3 and a-GaAs films (figure 4) [6][7][8]12].…”

“…The characteristics of such films differ from с-GaAs due to their complex structure and strong defect disordering. Film deposition from plasma produced by a powerful ion beam (PIB) enables to implement high-speed deposition and to form films on significant areas and on various substrates [10][11][12][13]. The peculiarities of electromigration in the films synthesized by the pulse ion ablation (PIA) have been insufficiently studied.…”