Annealing effect on electrical and photoconductive properties of Si implanted GaSe single crystal

Abstract

GaSe single crystals grown by Bridgman method have been doped by ion implantation technique. The samples were bombarded in the direction parallel to c-axis by Si ion beam of about 100 keV to doses of 1x10 16 ions/cm 2 at room temperature. The effects of Si implantation with annealing at 500 and 600 o C on the electrical properties have been studied by measuring the temperature dependent conductivity and photoconductivity under different illumination intensities in the temperature range of 100-320 K. It is observed that Si implantation increases the room temperature conductivity 10 -7 to 10 -3 (Ω-cm) -1 depending on the post annealing temperature. The analysis of temperature dependent conductivity shows that at high temperature region above 200 K, the transport mechanism is dominated by thermal excitation in the doped and undoped GaSe samples. At lower temperatures, the conduction of carriers is dominated by variable range hopping mechanism in the implanted samples. Annealing of the samples at and above 600 o C weakens the temperature dependence of the conductivity and photoconductivity. This indicates that annealing of the implanted samples activates Si-atoms and increases structural deformations and stacking faults. The same behavior was observed from photoconductivity measurements. Hence, photocurrent-illumination intensity dependence in the implanted samples obeys the power low I pc ∝ Φ n with n between 1 and 2 which is an indication of continuous distribution of localized states in the band gap.

Structural, electrical and optical properties of Ge implanted GaSe single crystals grown by Bridgman technique

“…The obtained room temperature resistivity value and the effect of implantation on conductivity behavior of as-grown GaSe single crystals are the same with the values obtained for N-and Si implanted GaSe [19,20,24]. Ln (σ) versus T -1 variations show three linear regions with different activation energies describing different conduction mechanisms at specific temperature intervals.…”

“…Thus, by using this technique, the target material can be doped with a wide range of atomic species at desired concentration. Recently, we carried out structural, electrical and optical characterization on N-and Si-implanted GaSe crystals grown in our laboratory [18][19][20]. During the implantation process because of high energies of accelerated ions, the structure can be disordered.…”

Influence of ion implantation on structural and photoconductive properties of Bridgman grown GaSe single crystals

“…The concentrations and depth profiles of the implanted atoms can be easily controlled in this technique [12]. We have recently investigated the electrical properties of N-and Si-implanted GaSe single crystals grown by Bridgman Technique [13,14].…”

Optical anisotropy in GaSe

“…This paper is a complementary work to our previous publications [9,10] where we reported electrical transport properties of the same structure. The optical anisotropy in the PL emission is clearly demonstrated with the dependence of the PL emission on the k vector of the exciting photons.…”

“…Preparation of the ampoules and growth processes were explained in our previous works [9,10]. The samples used in this study were prepared by cleaving an ingot parallel to the layers.…”