Effect of swift heavy ion Ag⁹⁺irradiation on the surface morphology, structure and optical properties of AgGaS₂single crystals

Abstract

AgGaS 2 (AGS) single crystals grown by chemical vapor transport (CVT) method were irradiated with Ag 9+ ions (120 MeV) with various ion fluences. The irradiation was carried out at room temperature (RT) and at liquid nitrogen temperature (LNT). A glancing angle x-ray diffraction (GAXRD) analysis reveals a huge lattice disorder at RT irradiation. This is observed from an increase in the full width at half maximum (FWHM) and a decrease in the intensity of the AGS (1 1 2) peak. However, there is no change in the FWHM of the (1 1 2) peak but the intensity slightly decreases at LNT irradiation. Also, AGS (3 0 3) peak is not observed for the samples irradiated with the fluences of 5 × 10 13 and 1 × 10 13 ions cm −2 at RT conditions. The GAXRD results show the decrease in degree of crystallinity upon ion irradiation at RT while there is not much degradation in crystallinity upon ion irradiation at LNT. But the LNT irradiation on AGS has its own effects. Atomic force microscope (AFM) studies show that the roughness of AGS increases on increasing the ion fluences at LNT and at RT. Also, it is found that there is an increase in the surface defects with fluences of Ag 9+ ion irradiation when compared to pristine AGS. UV-visible transmission spectra show that the percentage of transmission and bandgap energy decrease with increasing ion fluences and also that the peaks are broadened at LNT and at RT. The photoluminescence (PL) spectra were analyzed as a function of irradiation ion fluences in the AGS crystals at RT. It has been found that the emission intensities of band-to-band transition decrease with increase of ion fluences at LNT and at RT.

Effect of swift heavy ion (SHI) irradiation on the structural and optical properties of N implanted CVT grown ZnSe single crystals

“…The FWHM of as grown ZnSe is 0.111 whereas for the N implanted samples the values vary from 0.171 to 0.251 with implantation fluences. The intensity of diffraction peaks drastically decreases with ion fluence which should be related with the formation of defects and decrease in the crystallinity on the near surface region of ZnSe crystals [21,22]. The decrease in the crystallinity of this layer in the implanted with irradiated samples has been calculated from the indexed GIXRD planes (111) with respect to the Au irradiated sample.…”

“…The intensity of emission decreases as well as the asymmetric nature of broadening of the peaks occurs by Au irradiation in the implanted samples. This can be attributed to the presence of several recombination sites and high concentration of defects present in the irradiated samples [21,22]. These defects form random clusters of donor or acceptor leading to electrostatic potential fluctuation and are responsible for the appearance of density of tails states of valance and conduction bands in the band gap [20,32,33].…”

Effect of 100MeV O7+ ion beam irradiation on radio frequency reactive magnetron sputtered ZnO thin films

“…The intensity variation could be attributed to the creation of defects such as the ion tracks. The ion tracks were created in the ion-induced melt due to the mechanical stress arising from thermal expansion [16][17][18]. LNT irradiated ZnO thin film shows strong degradation as compared to the pristine and RT irradiated samples.…”

“…While there has been a lot of work directed towards improving the optical properties of ZnO using different deposition parameters and annealing of film under different conditions, there are only a few reports on swift heavy ion induced (SHI) modification of the optical properties of ZnO [13][14][15]. Swift heavy ion irradiation of materials has attracted much interest during the recent years since it is a unique tool to modify the properties of a material and provides an alternative to photons for introducing electronic excitations in materials [16][17][18][19]. When a swift heavy ion penetrates a solid, it slows down via two processes: (1) direct transfer of recoil energy to target atoms through elastic collisions, i.e., nuclear energy loss (Sn) and (2) electronic excitation and ionization of target atoms or inelastic collisions, i.e., electronic energy loss (Se).…”

Optimization of Luminescence due to SHI Irradiation on Cr‐Doped BiFeO3 (BFO) Thin Films

“…[21] The incident ion's mass, irradiation energy, and fluence have a significant impact on the radiationinduced changes. [22] When thin films are irradiated with swift heavy ions, the band gap reduction is a common phenomenon attributed either to increased crystallization or the formation of defect states in the forbidden energy band. [23] Hereby, bismuth ferrite materials are more suitable to prepare ferroelectric photovoltaic devices and to increase power conversion efficiency (PCE).…”