The open-circuit voltage in microcrystalline silicon solar cells of different degrees of crystallinity

Transport mechanisms and effective Schottky barrier height of ZnO/a-Si:H and ZnO/μc-Si:H heterojunction solar cells

“…These values were found to better describe our experiments while keeping the best possible with common values shown in literature. [16][17][18][19][20][21][22][23][24][25][26][27] Models used for the simulations include Fermi-Dirac statistics and Shockley-Read-Hall recombination. Amorphous layers were represented by a continuous DOS in the bandgap composed of exponential functions for band tails into the bandgap.…”

Why does the open-circuit voltage in a micro-crystalline silicon PIN solar cell decrease with increasing crystalline volume fraction?

“…A detailed analysis of the sensitivity of microcrystalline solar cells to the band tail and Gaussian defect densities can be found in a recent publication [1]. In brief, a higher value of these quantities gives rise to increased hole trapping at and near the P/I interface; therefore a high interface field and a collapse of the field over the volume of the absorber layer, resulting in a lower V OC [6] for the 'High F c ' case.…”

“…We have proposed an explanation [1] that is based partly on broader band tails and higher defect density when F c is high, since structural relaxation of the lc-Si:H network and passivation of grain boundary defects cannot properly take place due to the low amorphous silicon content in this well-crystallized material. Another very important reason [1] for the decrease in V OC is the assumption of a lower band gap for the more crystallized material, which will be analyzed in detail in this paper. This fact is confirmed experimentally by in situ Kelvin probe analysis [2] and photoluminescence [3].…”

Geometrical optimization and electrical performance comparison of thin-film tandem structures based on pm-Si:H andμc-Si:H using computer simulation

“…An analogous expression holds for the conduction band tail, with a characteristic energy width E UD . The material parameters for the μc-Si:H and pm-Si:H cells used in the numerical calculations originate from several references [18][19][20][21]. The main parameters of intrinsic layers introduced in our simulation are given in Table 1.…”