Non-contacting determination of carrier lifetime and surface recombination velocity using photothermal radiometry

Non-contacting measurements of photocarrier lifetimes in bulk- and polycrystalline thin-film Si photoconductive devices by photothermal radiometry

“…The fits were sensitive to the value of s 1 which determined the slope of the amplitude decay, whereas the value of s 2 was relatively unimportant, as long as it was much larger than s 1 , in agreement with earlier findings by Sheard et al using PTR signals. 4 Physically, this is as expected, since the back surface of the wafers was not polished and therefore presented a large specific area for recombination. The PC signal fittings were most sensitive to the recombination lifetime values, which decreased with increasing applied dc voltage.…”

“…21 The best-fitted and D values are well within the accepted norms of recombination lifetimes in Si. 4,22 Figure 5 shows the PC signal ͑amplitude and phase͒ vs applied voltage V dc data at two modulation frequencies. The electric-field E values utilized in the PC and the PTR signal fits were EϭV dc /2ϫ10 Ϫ3 V/m, reflecting the lateral dimensions of the sample.…”

“…Since the early photoacoustic studies of transport photoconductive phenomena in semiconductors, 1-3 an increasing amount of work has been reported in exploiting thermal-and carrier diffusion-wave effects in substrate Si wafers 4 and in active photoexcited devices 5 by means of infrared photothermal radiometry. The utility of this technique lies in its ability to yield electronic transport measurements in a nondestructive, noncontacting manner and, more fundamentally, in exploring near-surface electronic processes in semiconductors without the requirement for electrical contacts which are known to perturb the energetics of the interface.…”

Noncontact Lifetime Reconstruction in Continuously Inhomogeneous Semiconductors: Generalized Theory and Experimental Photothermal Results for Ion-Implanted Si

“…The experimental setup for the photothermal radiometry (PTR) method [6,7] used to measure the frequency dependencies ofthe SPD magnitude and phase is shown in Fig.4. A harmonically modulated Iaser beam obtained by modulating an Ar+ Iaser using an acousto-optic modulator (AOM) was slightly focused The curves are normalized to those obtained for non-implanted Si.…”

Minority carrier recombination lifetimes in n-type CdMgSe mixed crystals measured by means of the photothermal infrared radiometry

“…The thermal and plasma waves are the result of the illumination of the sample by the intensity mod− ulated beam of light. The theory and experiment of the PTR method was described in papers [10][11][12][13][14][15][16][17][18][19][20]. The PTR method was used to obtain information about carrier transport parameters such as carrier recombination lifetimes, surface recombination velocities and carrier diffusion coefficients.…”