Variation of the reflection coefficient of semiconductors in a wavelength range from 0.2 to 20 μm under the action of ultrasonic waves

The Dynamic Ultrasound Influence on the Diffusion and Drift of the Charge Carriers in Silicon p-n Structures

“…where W ph is an intensity of the illumination light, R -reflection coefficient, β -quantum Reduction of the reflection coefficient of the silicon surface due to the acoustostimulated diffusion of phosphorus into the semiconductor's depth was observed in [2]. Phenomenon of dynamic growth of L n induced by the ultrasound field was observed in work [9], this phenomenon being connected with reorientation of the complexes of defects, which include boron atoms, and with corresponding decrease of the carriers capture cross-section.…”

“…In particular, the increasing of the L n is preferred and a similarity of the specific features of the acoustostimulated increments of L n in [9] and I SC in given study are an evidence of this, namely presence of the US intensity threshold (see Figure 3(a)) and the characteristic time of the process -tens of minutes (see Figure 2). Besides, for λ = 600 nm, the expression for I SC should undergone a little modification: (2) where s is surface recombination rate, and D p -holes' diffusion coefficient inside the n region. Our measurements have shown that L n ≈ 120 µm for the investigated solar cells, hence, for 600-nm illumination 1 L n >> α and I SC does not practically depend on L n .…”

“…Recent time much attention is paid to the study of ultrasound influence on the defect structure and electrophysical properties of semiconductor structures [1][2][3][4][5][6][7][8]. In particular, it is revealed, that the broadering of a solar cell (SC) spectral sensitivity range [2], low-temperature annealing of radiating defects [3][4][5] and passivation of grain boundary defects [6] can be realized by the intensification of the defects diffusion and restructuring in a ultrasound field.…”

“…In particular, it is revealed, that the broadering of a solar cell (SC) spectral sensitivity range [2], low-temperature annealing of radiating defects [3][4][5] and passivation of grain boundary defects [6] can be realized by the intensification of the defects diffusion and restructuring in a ultrasound field. At the same time processes which occur in material under the acousto-induced nonequilibrium conditions are not clear till now and attract enhanced interest of researchers [7,8].…”

10.1007/s11455-008-3019-x

“…However, the ultrasonic treatment of a semiconductor at a threshold power level has certain specific features, which are apparently related to the production of defects in the near-surface region as described in [16,17]. Then, impurity atoms diffusing in the ultrasonic field can segregate at such defects and form impurity "clouds" (analogous to the Cottrell atmospheres [18]), which change the charge density in the surface states, as well as their energy spectrum (Fig.…”