Self-consistency and self-sufficiency of the photocarrier grating technique

Abstract

The recently suggested photocarrier grating technique appears to be the most reliable method available for the determination of the ambipolar diffusion length in hydrogenated amorphous silicon. We show that the technique can be made simpler than originally suggested, and that it is self-sufficient in the sense that all the required parameters can be determined by the same experimental setup. It is demonstrated that the various results obtained by the technique are self-consistent and that extremely accurate values of the ambipolar diffusion length can be determined.

Carrier diffusion in thin-film CH3NH3PbI3 perovskite measured using four-wave mixing

“…We note that a steady-state photocarrier grating method relying on a change of photocurrent induced by interference of continuous wave laser beams 47,48 was recently applied to organic-inorganic perovskite films. 32 In contrast to the approach used in Ref.…”

Radiation-induced defects in a-Si:H by 1.5MeV He4 particles studied by photoconductivity and photothermal deflection spectroscopy

“…4. L amb was obtained from a linear fit [10] with standard deviation represented by the error bars in Fig. 4, from which the uncertainty in the hole ls-product was deduced.…”

“…3 one can see the photocurrent I ph as a function of particle fluence, obtained by illumination with a 2 mW HeNe laser (632.8 nm). The ambipolar diffusion length, L amb , was obtained with the SSPG technique, from the measurement of the photoconductivities in the presence and the absence of a photocarrier grating, established on the sample by laser interference, for different values of the grating period [10]. The mobility-lifetime product of the minority-carrier holes, (ls) h , was then deduced from the relation…”

Steady-state photocarrier grating method of determining electronic states parameters in amorphous semiconductors

“…Some of the results are shown in Figs. [3][4][5][6][7][8][9]. The values of l e = 0.13 AE 10 À2 m 2 (V s) À1 , l h = 10 À4 m 2 (V s) À1 [16] and T = 293 K has been assumed.…”

“…One of the most promising methods of determining the values of diffusion length of carriers in amorphous semiconductors is based on the steady-state photocarrier grating (SSPG) model [1][2][3][4][5][6][7][8][9][10][11][12]. This technique uses an interference pattern obtained over the illuminated sample surface when two coherent radiation beams hit the sample at different angles of incidence (Fig.…”