Yazar "Güneş, Mehmet" için listeleme
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Atmospheric aging and light-induced degradation of amorphous and nanostructured silicon using photoconductivity and electron spin resonance
Saleh, Z. M.; Nogay, G.; Ozkol, E.; Yilmaz, G.; Şağban, Mehmet; Güneş, Mehmet; Turan, R. (Canadian Science Publishing, Nrc Research Press, 2014)Previous studies indicate that the dark conductivity in amorphous and microcrystalline silicon may increase or decrease with exposure to deionized water (DIW) or pure oxygen at 80 degrees C but always decreases with light ... -
The effect of aging on the dark conductivity and noise in hydrogenated microcrystalline silicon thin films
Güneş, Mehmet; Johanson, R. E.; Kasap, S. O.; Finger, F.; Lambertz, A. (Wiley-V C H Verlag Gmbh, 2010)Aging hydrogenated microcrystalline silicon in air is found to affect both the dark conductivity and the 1/f noise. For a sample with a crystalline volume fraction of 0.39, the conductivity decreased by three orders of ... -
The effects of air, oxygen and water exposure on the sub-bandgap absorption, the electronic conductivity and the ambipolar diffusion length in highly crystalline microcrystalline silicon films for photovoltaic applications
Güneş, Mehmet; Smirnov, V.; Finger, F.; Brueggemann, R. (Springer, 2020)Reversible and irreversible changes due to long term air and short term de-ionized water (DIW) or pure oxygen exposure were investigated in about 1 mu m thick hydrogenated microcrystalline silicon (mu c-Si:H) films deposited ... -
The effects of native and light induced defects on optoelectronic properties of hydrogenated amorphous silicon-germanium (a-SiGe:H) alloy thin films
Güneş, Mehmet; Yavas, M. E. D.; Klomfass, J.; Finger, F. (Springer, 2010)Effects of native and light induced defects states in hydrogenated amorphous silicon-germanium alloy thin films with different Ge concentrations have been investigated by using steady-state photoconductivity, dual beam ... -
Investigation of light induced degradation in hydrogenated amorphous silicon-germanium alloy thin films using temperature dependent photoconductivity
Güneş, Mehmet; Turan, E.; Yılmaz, G. (Wiley-V C H Verlag Gmbh, 2010)Light induced degradation of undoped hydrogenated amorphous silicon-germanium (a-SiGe:H) alloys with different Ge contents has been investigated using intensity and temperature dependence of photoconductivity between 78K ... -
Investigation of meta- and in-stability effects in hydrogenated microcrystalline silicon thin films by the steady-state measurement methods
Güneş, Mehmet; Cansever, Hamza; Yılmaz, Gökhan; Sagban, Muzaffer H.; Smirnov, Vladimir; Finger, Friedhelm; Brueggemann, Rudolf (Canadian Science Publishing, Nrc Research Press, 2014)Metastability effects because of atmospheric exposure, high purity gasses, and deionized water in hydrogenated microcrystalline silicon thin films with different crystalline volume fractions were studied using well accepted ... -
Investigation of metastability and instability effects on the minority carrier transport properties of microcrystalline silicon thin films by using the steady-state photocarrier grating technique
Cansever, Hamza; Güneş, Mehmet; Yılmaz, Gökhan; Sagban, H. Muzaffer; Smirnov, Vladimir; Finger, Friedhelm; Brueggemann, Rudolf (Canadian Science Publishing, Nrc Research Press, 2014)Metastability effects in hydrogenated microcrystalline silicon thin films due to air, high purity nitrogen, helium, argon, and oxygen were investigated using temperature-dependent dark conductivity, photoconductivity, and ... -
The native and metastable defects and their joint density of states in hydrogenated amorphous silicon obtained from the improved dual beam photoconductivity method
Güneş, Mehmet; Melskens, Jimmy; Smets, Arno H. M. (American Institute of Physics Inc., 2023)In this study, undoped hydrogenated amorphous silicon (a-Si:H) thin films deposited under moderate dilution ratios of silane by radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) have been investigated ... -
Rapid Reversible Degradation of Silicon Thin Films by a Treatment in Water
Turan, Elif; Yılmaz, Gökhan; Smirnov, Vladimir; Finger, Friedhelm; Güneş, Mehmet (Iop Publishing Ltd, 2012)Metastability effects in amorphous and microcrystalline silicon thin films induced by exposure to atmospheric gases and water are investigated. A simple procedure is described which allows studying such effects in a ... -
Reversible and irreversible effects after oxygen exposure in thick (> 1 mu m) silicon films deposited by VHF-PECVD on glass substrates investigated by dual beam photoconductivity
Yılmaz, Gökhan; Cansever, Hamza; Sagban, H. Muzaffer; Güneş, Mehmet; Smirnov, Vladimir; Finger, Friedhelm; Brueggemann, Rudi (Canadian Science Publishing, Nrc Research Press, 2014)Metastability and instability effects due to oxygen exposure in thick intrinsic hydrogenated microcrystalline silicon films deposited by very high frequency plasma enhanced chemical vapour deposition on smooth glass ... -
Understanding the Origin of Thermal Annealing Effects in Low-Temperature Amorphous Silicon Films and Solar Cells
Wilken, Karen; Güneş, Mehmet; Wang, Shuo; Finger, Friedhelm; Smirnov, Vladimir (WILEY-V C H VERLAG GMBH, 2022)A detailed investigation of the effects of prolonged postdeposition annealing on the performance of amorphous silicon (a-Si:H) solar cells and the properties of individual a-Si:H layers that are fabricated at low temperature ...
