Carrier dynamics at surface and interface in hydrogenated amorphous silicon observed by the transient grating method

Abstract

Carrier dynamics at a free surface and an interface in a glow discharge hydrogenated amorphous silicon (a:Si:H) film were observed by a transient grating method. The diffusion coefficients and lifetimes at the surface and in the bulk were determined separately by exciting carriers by selecting the wavelength of the excitation light. The diffusion coefficients and lifetimes in the bulk, at the surface and interfaces decreased in the following order: bulk, a:Si:H free surface, a-Si:H/substrate interface, a-Si C:H/a-Si:H interface.

Determination of Generation Lifetime in Trap‐Rich and Layered Semiconductors by Metal‐Oxide‐ Semiconductor Measurements

“…11 we found a spread for 9 between 20 ~ts and 4 -10 -12 S. 11 we found a spread for 9 between 20 ~ts and 4 -10 -12 S.…”

“…The neglect of the oxide charges and the work function differences is justified by the fact that they do not contribute to the dynamic properties of the MOS diode. We write dn = --cnNT(1 --f)n + enNTf [10] dp -cpN~fp + epNT(1 --f) [11] dr-In equilibrium d/dt = O, f = fo, n = no, and p = P0 is valid so that eJcn = n0(1fo)/fo = nl [12] %/% = pff0/(1 -f0) = Pl [13] With the definitions [16] so that dp + ~p ) -% ~ + Pl -fo(Po + Pl ~f _ [17] P0 + P, From the equilibrium condition of Eq. In the present work, however, just one interface is of interest, namely, the oxide/a-Si interface.…”

Improvement of amorphous silicon n-i-p solar cells by incorporating double-layer hydrogenated nanocrystalline silicon structure

“…Due to the compositional disorder and morphological fluctuation at the i/p interface, a large amount of dangling bonds may exist and act as recombination centers or deep trapping centers [1]. Tasaki et al reported that the interface states cause abrupt band bending at the i/p interface and reduce the electric field in the i layer, consequently, the recombination rate near this interface region increases significantly [2].…”

Numerical simulation of barrier height effect on output parameters, for a a-Si:H/nc-Si:H based solar cell

“…Another parameter which can affect these performances is the quality of the interfacial matching at the i/p interface and by the contacts to the doped layers as well [1]. It has been shown experimentally and with computer modelling, that hole barrier at the front contact/ p-layer interface can also influence hydrogenated amorphous silicon (a-Si:H) n-i-p solar cell performances [2].…”