WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 13Citation - Scopus: 14Electronic Transport Properties of Microcrystalline Silicon Thin Films Prepared by Vhf-Pecvd(Springer Verlag, 2004) Okur, Salih; Güneş, Mehmet; Göktaş, Oktay; Finger, Friedhelm; Carius, ReinhardSteady-state photocarrier grating (SSPG) and steady-state photoconductivity, σph, experiments have been carried out to investigate the electronic transport properties of undoped hydrogenated microcrystalline silicon (μc-Si: H) films prepared with very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD). Material with different crystalline volume fractions was obtained by variation of the silane concentration (SC) in the process gas mixture. Pure amorphous silicon material was investigated for comparison. The ambipolar diffusion length, L amb, which is dominated by the minority carrier properties, is obtained both from the best fit to the experimental photocurrents ratio, β, versus grating period (Λ), and from the "Balberg plot" for the generation rates between 1019 and 1021 cm -3 s-1. Lamb increases from 86 nm with increasing SC and peaks around 200 nm for the SC = 5.6% and decreases again for higher SCs. Lamb values obtained from the intercept of the Balberg plot result in a small difference of around 5% for most of the samples. Minority carrier mobility-lifetime (μτ)-products are much lower than those of majority carriers, however, both majority and minority carrier μτ-products in microcrystalline silicon are higher than those of undoped hydrogenated amorphous silicon. The grating quality factor (γ 0) changes from 0.70 to 1.0 indicating almost negligible surface roughness present in the samples.Conference Object Citation - WoS: 5Citation - Scopus: 5Photoconductivity Spectroscopy in Hydrogenated Microcrystalline Silicon Thin Films(Springer Verlag, 2003) Güneş, Mehmet; Akdaş, Deniz; Göktaş, Oktay; Carius, Reinhard; Klomfaß, Josef; Finger, FriedhelmSteady-state photoconductivity and sub-bandgap absorption measurements by the dual-beam photoconductivity (DBF) method were carried out on undoped hydrogenated microcrystalline silicon thin films prepared by VHF-PECVD and hot-wire chemical vapor deposition. The results are compared with those of the constant-photocurrent method (CPM) and photothermal deflection spectroscopy (PDS). It is found that DBP, CPM, and PDS provide complementary data on the optoelectronic processes in microcrystalline silicon.