Light illumination effect on the electrical and photovoltaic properties of In6S7 crystals

Qasrawi, AF
Hasanlı, Nızamı
The electrical and photoelectrical properties of In6S7 crystals have been investigated in the temperature regions of 170-300 K and 150-300 K, respectively. The dark electrical analysis revealed the intrinsic type of conduction. The energy band gap obtained from the temperature-dependent dark current is found to be 0.75 eV. It is observed that the photocurrent increases in the temperature range of 150 K up to T-m = 230 K and decreases at T > T-m. Two photoconductivity activation energies of 0.21 and 0.10 eV were determined for the temperature ranges below and above Tm, respectively. The photocurrent (I-ph)-illumination intensity (F) dependence follows the law I-ph alpha F-gamma. The value of. decreases when the temperature is raised to T-m, then it starts increasing. The change in the value. with temperature is attributed to the exchange in role between the recombination and trapping centres in the crystal. The crystals are found to exhibit photovoltaic properties. The photovoltage is recorded as a function of illumination intensity at room temperature. The maximum open-circuit voltage and short-circuit photocurrent density, which are related to an illumination intensity equivalent to one sun, are 0.12 V and 0.38 mA cm(-2), respectively.


Photoelectronic and electrical properties of CuIn5S8 single crystals
Qasrawi, AF; Hasanlı, Nızamı (Wiley, 2003-01-01)
To identify the impurity levels in CuIn5S8 single crystals, the dark electrical conductivity and photoconductivity measurements were carried out in the temperature range of 50-460 K. The data reflect the intrinsic and extrinsic nature of the crystals above and below 300 K, respectively. Energy band gaps of 1.35 and 1.31 eV at 0 K and 300 K, were defined from the dark conductivity measurements and the photocurrent spectra, respectively. The dark and photoconductivity data in the extrinsic temperature region ...
Visible photoluminescence from chain Tl4In3GaSe8 semiconductor
Hasanlı, Nızamı (IOP Publishing, 2006-07-05)
The emission band spectra of undoped Tl4In3GaSe8 chain crystals have been studied in the 16-300 K temperature range and the 535-740 nm wavelength range. Two visible photoluminescence bands centred at 589 and 633 nm were observed at T = 16 K. Variations of both bands have been investigated over a wide range of laser excitation intensity ( 3 x 10(-4) -1.2 W cm(-2)). Radiative transitions with energies of 2.10 and 1.96 eV from two upper conduction bands to two shallow acceptor levels (0.03 and 0.01 eV), respec...
Reflectance spectra and refractive index of a Nd : YAG laser-oxidized Si surface
Aygun, G; Atanassova, E; Turan, Raşit; Babeva, T (Elsevier BV, 2005-02-15)
The reflectance spectra and refractive index of Nd:YAG laser-oxidized SiO2 layers with thicknesses from 15 to 75 nm have been investigated with respect to the laser beam energy density and substrate temperature. Thickness and refractive index of films have been determined from reflectance measurements at normal light incidence in the spectral range 300-800 nm. It was found that the oxide-growth conditions at higher substrate temperatures and laser powers greater than 3.36 J cm(-2) provides a better film qua...
Investigation of carrier scattering mechanisms in TIInS2 single crystals by Hall effect measurements
Qasrawi, AF; Hasanlı, Nızamı (Wiley, 2004-05-01)
TlInS2 single crystals are studied through the conductivity and Hall effect measurements in the temperature regions of 100-400 and 170-400 K, respectively. An anomalous behavior of Hall voltage, which changes sign below 315 K, is interpreted through the existence of deep donor impurity levels that behave as acceptor levels when are empty. The hole and electron mobility are limited by the hole- and electron-phonon short range interactions scattering above and below 315 K, respectively. An energy level of 35 ...
Electron-phonon short-range interactions mobility and p- to n-type conversion in TlGaS2 crystals
Qasrawi, AF; Hasanlı, Nızamı (Wiley, 2006-02-01)
The conductivity type conversion from p- to n-type at a critical temperature of 315 K in TlGaS2 crystals is observed through the Hall effect measurements in the temperature range of 200-350 K. The analysis of the temperature-dependent electrical resistivity, Hall coefficient and carrier concentration data reveals the extrinsic type of conduction with donor impurity levels that behave as acceptor levels when are empty. The data analysis allowed the calculation of hole and electron effective masses of 0.36m(0...
Citation Formats
A. Qasrawi and N. Hasanlı, “Light illumination effect on the electrical and photovoltaic properties of In6S7 crystals,” JOURNAL OF PHYSICS-CONDENSED MATTER, pp. 4609–4614, 2006, Accessed: 00, 2020. [Online]. Available: