Dielectric and transport properties of thin polycrystalline CdTe films

DC electric and photoelectric measurements of CdTe thin films in Schottky-barrier cells

“…Thus, an analysis of the temperature dependence of ohmic and SCL currents, which is associated with the extrinsic behavior yields a total trap concentration N t D3.85 Â 10 22 m À3 located at 0.58 eV above the valence band edge. These values for the CdTe samples are in good agreement with values of N t =1.08 Â 10 22 m À3 and E t =0.61 eV calculated by Dharmadhikari [17], and also with values of N t up to 3 Â 10 22 m À3 and E t =0.56 eV determined by Basol and Stafsudd [18]. Fig.…”

Trapping parameters in evaporated CdTe thin films showing space-charge-limited conductivity†

“…l V a square-law region ( J a V 2 ) was observed; at voltages greater than 0.5V the current increased rapidly, obeying the relation J a V" where n-6. Similar behaviour was also observed by Dharmadhikari (1983).…”

“…The results presented show a relative permittivity value of 10.68 and ohmic conduction at low voltages followed by square-law and power-law SCL currents as the voltage increases, in contrast to a relative permittivity value of 9.6 and the absence of square-law SCL behaviour in results previously reported by lsmail and Gould (1989). Results similar to those reported in the present work have been observed by Dharmadhikari (1983). …”

“…This is higher than that similarly derived for films deposited at 300°C (Ismail and Gould 1989), although the materials used in the two studies were obtained from different suppliers. It is also higher than the low relative permittivity value of 8.7 reported by Dharmadhikari (1983), which was related to submicroscopic inhomogeneities, low packing densities and a smaller mean grain size than that for samples prepared using the same experimental arrangement as in the present case (Ismail and Gould 1989). There was no indication of any capacitance variations inconsistent with a parallelplate model and thus no need in this case to derive the permittivity using a more complex model (Gould et al 1991).…”

Electrical conduction mechanisms of CdTe quantum dots/p-si heterojunction

“…As a result, the absorber layer thickness in nanostructure solar cells can be as thin as 150 nm instead of several micrometers in microstructure thin film solar cells [7,8]. Previous studies show that the conduction mechanisms in CdTe junctions can be thermionic emission type [9] or a space charge limited conduction (SCLC), which is normally dominated either by traps located at a discrete energy level [10,11] or by traps distributed exponentially within the band gap [11][12][13]. Additionally, it is seen that both traps types belong to the space charge limited conduction can be presented but each one becomes a dominant in a certain voltage range [14].…”