Single Crystal Photodetectors Research Articles

Highly-Polarized Solar-Blind Ultraviolet Organic Photodetectors.

Developing high-performance polarization-sensitive ultraviolet photodetectors is crucial for their application in military remote sensing, detection, bio-inspired navigation, and machine vision. However, the significant absorption in the visible light range severely limits the application of polarization-sensitive ultraviolet photodetectors, such as high-quality anti-interference imaging. Here, based on a wide-bandgap organic semiconductor single crystal (trans-1,2-bis(5-phenyldithieno[2,3-b:3',2'-d]thiophen-2-yl)ethene, BPTTE), high-performance polarization-sensitive solar-blind ultraviolet photodetectors with a dichroic ratio close to 4.26 are demonstrated. The strong anisotropy of two-dimensional grown BPTTE single crystals in molecular vibration and optical absorption has been characterized by various techniques. Under voltage modulation, stable and efficient detection of polarized light has been demonstrated, attributed to the intrinsic anisotropy of transition dipole moment in the bc crystal plane, rather than other factors. In final, high-contrast polarimetric imaging and anti-interference imaging are successfully demonstrated based on BPTTE single crystal photodetectors, highlighting the potential of organic semiconductors for polarization-sensitive solar-blind ultraviolet photodetectors. This article is protected by copyright. All rights reserved.

CVT grown CuSe single crystals: Unveiling photodetection advancements and thermoelectric promise

Over the past few decades, transition metal chalcogenides garnered global recognition for their noteworthy contributions to the modeling and engineering of electronic, optoelectronic, and thermoelectric devices to improve overall device performance. In the current investigation, the first ever growth of CuSe single crystals is achieved utilizing the chemical vapor transport technique with iodine serving as a transporting medium. The ascertainment of the hexagonal unit cell configuration in the grown CuSe crystals with the P63/mmc space group is substantiated via powder X-ray diffraction examination. The micro-surface characteristics exhibited planar facets outlined by layer boundaries, signifying crystal development through a mechanism reliant on layer growth. The direct optical bandgap of 1⋅64 eV for CuSe single crystals is unveiled by optical reflectance spectrum, demonstrating its aptitude for incorporation into photodetectors. The Raman spectrum manifested a prominent peak at 259 cm−1, aligning to Ag1 vibrational mode. The exploration of temperature-induced fluctuations in the power factor and figure of merit unveiled a progressive increase with rising temperatures. The optimal ZT parameter for the CuSe single crystals attains 0⋅058 at 523 K. The thermogravimetric patterns of CuSe single crystals exhibited singular step decomposition, exemplified by an average weight reduction of 25⋅49 % across the temperature spectrum from ambient to 813 K. The current−voltage (I–V) features of the fabricated CuSe single crystal photodetector are assessed under biasing voltage set at 20 mV at ambient temperature. Under a bias voltage of 20 mV and a polychromatic light intensity of 50 mW/cm2, the achieved responsivity is 4335⋅57 μA/W and a detectivity of 135 × 106 Jones. The photoresponse and thermoelectric examination of CuSe crystals alludes to their potential utility in innovative applications on the horizon.

Fabrication of ZnSnO3 single crystal films on sapphire substrates by pulsed laser deposition for solar-blind photodetectors

ZnSnO3 single crystal films were prepared on c-plane sapphire substrates using pulsed laser deposition and post-annealing methods. For the as-grown sample at 700 °C, post-annealing at 700 °C resulted in a significant improvement in the crystalline quality of the single crystal films, while post-annealing at 800 °C led to decomposition of ZnSnO3. Compared with the amorphous and mixed crystal ZnSnO3-based photodetectors (PDs), the single crystal ZnSnO3-based PD has a better light-to-dark current ratio (1.32 × 106) and higher responsivity (8.71 A/W) at 5 V under 254-nm UV (1.1 mW/cm2) illumination. Such a good performance serves as resounding validation of the remarkable potential of ZnSnO3 epitaxial films in the context of solar-blind PDs.

Dimensionality Engineering of Lead Organic Chalcogenide Semiconductors.

Two-dimensional (2D) metal organic chalcogenides (MOCs) such as silver phenylselenolate (AgSePh) have emerged as a new class of 2D materials due to their unique optical properties. However, these materials typically exhibit large band gaps, and their elemental and structural versatility remain significantly limited. In this work, we synthesize a new family of 2D lead organic chalcogenide (LOC) materials with excellent structural and dimensionality tunability by designing the bonding ability of the organic molecules and the stereochemical activity of the Pb lone pair. The introduction of electron-donating substituents on the benzenethiol ligands results in a series of LOCs that transition from 1D to 2D, featuring reduced band gaps (down to 1.7 eV), broadband emission, and strong electron-phonon coupling. We demonstrated a prototypical single crystal photodetector with 2D LOC that showed the dimensionality engineering on the transport property of LOC semiconductors. This study paves the way for further development of the synthesis and optical properties of novel organic-inorganic hybrid 2D materials.

Bridgman grown CuSbS2 single crystal and its application as photodetector and potential thermoelectric material

Crystal of copper antimony disulphide (CuSbS2) measuring 4.5 cm in length and 0.8 cm in diameter was successfully grown using the vertical Bridgman technique (VBT). The orthorhombic unit cell structure and pure CuSbS2 phase of the grown crystal was confirmed by the powder X-ray diffraction and was well supported by Raman spectra. The stoichiometry of the grown crystal was confirmed by energy dispersive X-ray analysis and field emission scanning electron microscopy revealed that crystal is grown by layer growth mechanism. The Raman spectra has shown the presence of peak at 319.32 cm−1 corresponding to Sb-S bonds whereas peaks at 445.03 cm−1 and 257.27 cm−1 corresponds to S-S and Cu-S bonds. The photoluminescence spectra taken at room temperature with 488 nm excitation wavelength displays emission in different regions of the visible spectrum. Optical absorbance spectra shows that CuSbS2 single crystal possess direct bandgap of 1.57 eV which is suitable for solar cell application. The Seebeck coefficient is positive over the entire temperature range, demonstrating the sample's p-type semiconducting nature and corroborates our Hall effect measurements. Using electrical conductivity and lattice thermal conductivity values we calculated thermoelectric figure of merit i.e., ZT whose value comes nearly 0.988 at 503 K which stands in competition with reported values of the other grown crystal. Thermogravimetric (TG) curve has shown two step decomposition at four different heating rates of 5, 10, 15 and 20 K/min which is also confirmed from DTG (differential thermogravimetric analysis) curves. At room temperature, the I-V characteristics of prepared CuSbS2 single crystal photodetector are measured for parallel to plane and perpendicular to plane configuration, with various biasing voltages at 50 mW/cm2. At room temperature, a bias voltage of 0.1 V with a light intensity of 50 mW/cm2 yields responsivity and detectivity of 30 mA/W and 32.84 × 106 Jones for ⊥ to plane, which is comparable to the reported values of other materials.

Growth and High-Performance Photodetectors of CsPbBr3 Single Crystals.

Organic-inorganic hybrid perovskites have demonstrated exceptional photovoltaic properties, making them highly promising for solar cells and photodetectors (PDs). However, the organic components of these materials are vulnerable to heat and strong light illumination, limiting their application prospects. All-inorganic cesium-based perovskite PDs, on the other hand, possess enhanced thermal tolerance and stability, making them ideal for perovskite applications. The utilization of a ternary mixture solvent and additives in combination with single crystal (SC) growth has enabled the production of highly crystalline SCs with a defect density of 3.79 × 109 cm-3. The performance of the SC PDs had been evaluated using metal-semiconductor-metal devices, which demonstrated excellent results with a dark current as low as 0.198 μA at 10 V bias, on-off ratios exceeding 103, and a response time of shorter than 1 ms.

Enhancement of CsPbBr3 Perovskite Single-Crystal Photodetector Performance via Zr Ion Implantation

All-inorganic halide perovskite single crystals have attracted significant attention in optoelectronic fields on account of their outstanding optoelectronic properties. Photodetectors (PDs) based on CsPbBr3 single crystal exhibit high responsivity (R) and external quantum efficiency (EQE) due to the direct optical band gap, large optical absorption throughout the visible spectrum range, and long-term stability. Herein, we prepared the centimeter-size CsPbBr3 perovskite single crystal and utilized Zr ion implantation to modify the photoelectric properties of single crystals. The optical band gap of the CsPbBr3 single crystal decreases from 2.24 to 2.12 eV, and the absorption intensity increases after Zr ion implantation. The R and EQE of the CsPbBr3 single crystal photodetector modified by Zr ion implantation are 1.0 A W–1 and 294%, respectively, with a light intensity of 3.8 mW cm–2 and a 5 V bias under 425 nm illumination, which are ten times larger than that of the pristine devices. Meanwhile, the first-principles calculation results show that the introduction of Zr ions decreases the band gap and that the Zr 4d orbit contributes to the conduction band minimum (CBM), which facilitates carrier transport in Zr ion implanted CsPbBr3 single crystals. The results show that Zr ion implantation is an effective strategy to improve the performance of the CsPbBr3 single-crystal-based PDs.

Germanane and (3‐Hydroxypropyl)germanane as Single Crystal Photodetectors

Abstract2D materials are being widely investigated for their potential application in light‐detecting devices. Very recently, a spin‐coated flexible 2D germanium‐based photodetector with great photocurrent density and responsivity as well as short rise and decay time is presented by Liu et. al. In this paper, the solid‐state single flake photodetector base on either pure germanane or (3‐hydroxypropyl)germanane is reported. Both prepared photodetectors while irradiated with different wavelengths of light exhibit outstanding responsivity of 1157 mA W−1 for GeH and 362 mA W−1 for (3‐hydroxypropyl)germanane, which exceeds Liu's flexible reported GeH photodetector (22 µA W−1) by more than five orders of magnitude. These constructed photodetectors also exhibit rise and fall times lower than 20 ms, which is also significantly faster than the GeH photodetector reported by Liu with rise and decay times 240 and 740 ms, respectively.

Lead-Free Double Perovskite Semiconductor with Rigid Spacer-Induced High-Tc Dielectric Switch Features.

Layered hybrid perovskites possess exceptional semiconductor features and structural versality, making them viable candidates for developing multifunctional dielectric phase-transition materials (PTMS). However, most PTMs based on layered hybrid perovskites still suffer from Pb toxicity and low operating temperature. The recently developed hybrid double perovskites provide a new routine to designed PTMs with desired working performance and environment-friendly chemical compositions. Herein, using rigid aromatic cations as templates, we have successfully synthesized a novel double perovskite (benzylammonium)4 AgBiBr8 (1), which consists of corner-sharing AgBr6 and BiBr6 layers and benzylammonium cations. Notably, 1 exhibits a high-temperature first-order reversible solid-state phase transition at 383/387 K (cooling/heating) and switchable dielectric performance around the temperature. Compared with the soft organic chain version of the compound, the phase transition temperature of 1 shows a large enhancement of 99 K, validating the correctness of the designing strategy. In addition, 1 also exhibits semiconductor characteristics with a calculated bandgap of 2.34 eV and an optical bandgap of 2.29 eV. Remarkably, the single crystal photodetector of 1 shows a low dark current (2.12×10-13 A), a high on/off ratio (1.77×103 ), and a fast response (τrise =125 μs and τdecay =419 μs). Such a lead-free phase transition material combined with semiconductor properties provides a new strategy to develop environmentally friendly multifunctional materials.

On the photoresponse regulations by deep-level traps in CsPbBr3 single crystal photodetectors

The all-inorganic halide perovskite CsPbBr3 has attracted significant attention owing to its excellent opto-electronic properties. However, deep-level traps within the material are significant for the properties of CsPbBr3 based opto-electronic devices. In this study, the effects of deep-level traps on the photoresponse characteristics of CsPbBr3 photodetectors were thoroughly studied. By tailoring the illumination combinations where 532 nm light emitting diode (LED) illumination corresponds to the band-to-band excitation of photo-carriers and 648 nm LED illumination corresponds to sub-band excitation by the deep-level traps, it is proven that the device photoresponse performance is improved by the existence of deep-level traps. The photoresponsivity was enhanced by ∼63.64% (from 0.44 to 0.72 A W−1) under 3.18 μW cm−2 532 nm LED illumination. The rise/fall time was reduced by 21.95% (from 20.5 to 16.0 ms)/25.47% (from 21.2 to 15.8 ms). The underlying physical mechanisms of deep level trap-induced modulations on the photoresponse performance of the CsPbBr3 photodetector were revealed and discussed. By further systematic simulation of the effects of material properties on the photoresponse regulation, it was concluded that a shorter carrier lifetime, higher carrier mobility, higher trap concentration, and deeper trap level could improve the photoresponse of the CsPbBr3 photodetector. This study aims to clarify the physical relation between material properties and device performance and provide guidance for high-performance CsPbBr3 photodetector design.

Weak X-Ray to Visible Lights Detection Enabled by a 2D Multilayered Lead Iodide Perovskite with Iodine-Substituted Spacer.

Broadband photodetectors (PDs) with low detection limits hold significant importance to next-generation optoelectronic devices. However, simultaneously detecting broadband (i.e., X-ray to visible regimes) and weak lights in a single semiconducting material remains highly challenging. Here, by alloying iodine-substituted short-chain cations into the 3D FAPbI3 (FA = formamidine), a new 2D bilayered lead iodide hybrid perovskite, (2IPA)2 FAPb2 I7 (1, 2IPA = 2-iodopropylammonium), that enables addressing this challenge is reported. Such a 2D multilayered structure and lead iodide composition jointly endow 1 with a minimized dark current (6.04 pA), excellent electrical property, and narrow bandgap (2.03eV), which further gives it great potential for detecting broadband weak lights. Consequently, its high-quality single crystal PDs exhibit remarkable photoresponses to weak ultraviolet-visible lights (377-637nm) at several tens of nW cm-2 with high responsivities (>102 mA W-1 ) and significant detectivities (>1012 Jones). Moreover, 1 has an excellent X-ray detection performance with a high sensitivity of 438 µC Gy-1 cm-2 and an ultralow detection limit of 20 nGy s-1 . These exceptional attributes make 1 a promising material for broadband weak lights detection, which also sheds light on future explorations of high-performance PDs based on 2D hybrid perovskites.

Metal-organic framework single crystal infrared photodetector

Metal–organic frameworks (MOFs) are an emerging class of functional materials possessing the coupled optical and electrical responses necessary for the operation of modern optoelectronic devices. Yet, the realization of near infrared MOF-based photodetector is still a challenge. Here, we report on the MOF single crystal photodetector with 600–1000 nm spectral range, overlapping with the efficient optical absorption of the MOF (HKUST-1), converting the light energy to electric one. We detect that 0.1 s response rate of the detector turned out to be higher than the previously announced MOF-based photodetectors, that is due to the fairly fast and reversible process of desorption of coordinated water molecules underlying the mechanism of charge carrier generation. We also confirm the 1 mJ cm−2 fluence for the threshold photodetection due to a photostimulated change in the optical properties of the MOF, rather than its degradation, which paves the way to fast and multiple detection of a low-intensity infrared laser light on the MOF single crystal.

Improved optoelectronic performance from the internal secondary excitation of MAPbCl3-MAPbBr3 single crystal photodetectors

Single crystal (SC) MAPbBr 3 and MAPbCl 3 perovskite are considered promising materials for fabricating high-performance photodetectors (PDs) due to their impressive optoelectronic properties and good chemical stability. Structural modification of PDs is the fundamental solution to improve performance. In this paper, we designed a simple structure diagram considering photoelectric properties and the possibility of epitaxial crystal growth. Then a solution height restriction method (SHR) was used to grow the crystal and make the internal secondary excitation feasible. X-ray rocking curves (XRC) of MAPbBr 3 -SHR SCs show the quality of crystal under this growth method is excellent. X-ray photoelectron spectroscopy (XPS) measurements and Energy-dispersive X-ray spectroscopy (EDS) indicate element diffusion exists in the interface. Photoluminescence spectra (PL) and the photoelectric performance test have proved the existence and validity of the internal secondary excitation of crystals. Based on the above analysis, it was demonstrated that the inner MAPbCl 3 single-crystal enhances the optoelectronic performance of MAPbCl 3 -MAPbBr 3 crystals by the internal secondary excitation effect.

Ultrafast Response of Centimeter Scale Thin CsPbBr3 Single Crystal Film Photodetector for Optical Communication.

The photodetector (PD) is the key component to realize efficient optoelectronic conversion signal in the visible light communication (VLC) system. The response speed directly determines the bandwidth of the whole system. Metal halide perovskite is a neotype of low-cost solution processing semiconductor, with strong optical absorption, low trap density, and high carrier mobility, thus has been widely explored in photoelectric detection applications. However, previously reported perovskite polycrystalline photodetectors exhibit limited response speed due to the existence of grain boundaries. Here, an improved confined space method is developed through adjusting the heating area to control nucleation, resulting in centimeter scale fully inorganic perovskite CsPbBr3 thin single crystal films (SCFs) (<40µm). The smooth surface and high crystallinity of CsPbBr3 SCFs render admirable exciton lifetime. The planar metal-semiconductor-metal photodetector using CsPbBr3 SCF as the photosensitive layer demonstrates a limit response time of 200/300ns and a VLC within 100-500kHz frequency for both 365nm and white light, which is superior to previously reported CsPbBr3 polycrystalline filmand single crystal photodetectors.

Unraveling the Effect of Halogen Ion Substitution on the Noise of Perovskite Single-Crystal Photodetectors.

Halide mixing in perovskites has been an efficient way to engineer the bandgap, stability, and charge carrier mobility of lead halide perovskites, while its effect on the noise of lead halide perovskite photodetectors is still unknown. We present the preparation of mixed halide methylammonium lead perovskite single crystals by the solution temperature-decreasing method. Planar-structured photodetectors were constructed on the basis of these mixed halide perovskite single crystals. The effect of halogen ion substitution on the noise of devices was investigated by analyzing their dark current spectra. It is shown that the single-crystal photodetectors with higher levels of chloride suffer from larger noise thus have lower detectivity. Density functional theory calculations have also been proposed to reveal the effect of halogens on band structure. These results provide a comprehensive understanding of mixed halide perovskites and may help in the design and preparation of higher-performance devices.

Cryotronic Low‐Powered Strained Polymorphic Photodetector Functionalized by Palladium Incorporated Tin Diselenide

AbstractResearchers’ challenging task is to develop a material that can bear extreme environmental conditions. In this context, ‘metal dichalcogenide’ based solid‐state devices are highly beneficial for cryogenic optoelectronic applications but rarely reported. Herein, novel meta‐materials PdxSn1−xSe2 (x = 0.0, 0.2, 0.4) and their photodetector application are introduced. These ternary crystals are grown by direct vapour transport (DVT) technique in which palladium incorporated SnSe2 crystals exhibit polymorphism of hexagonal‐orthorhombic multiphase. PdxSn1−xSe2 (x = 0.0, 0.2, 0.4) single crystal photodetectors (SCPDs) demonstrate excellent photodetection in which SCPD functionalized by Pd0.4Sn0.6Se2 displays superior photoresponse. Cryogenic temperature directed blue‐shifting and sharpening of Raman peak displays noteworthy thermal‐sensing ability. Captivatingly, 10 µV low‐powered Pd0.4Sn0.6Se2 SCPD demonstrates substantial photodetection with 2.41 × 108 Jones detectivity at the cryogenic temperature of 10 K. To the best of the authors’ knowledge, a photosensor that displays excellent photodetection at a very low bias of 10 µV applied to the detector at the cryogenic temperature of 10 K is reported for the first time by them in present investigation. Higher stability, reproductiveness, and a low‐powered operating ability at a cryogenic temperature of 10 K declares Pd0.4Sn0.6Se2 as a potential candidate to design next‐generation low‐powered optoelectronic applications in cryotronics.

Highly Sensitive Photoelectric Detection and Imaging Enhanced by the Pyro-Phototronic Effect Based on a Photoinduced Dynamic Schottky Effect in 4H-SiC.

Silicon carbide (SiC), one of the third-generation semiconductor materials with excellent electrical and optoelectronic properties, is ideal for high light-sensing performance. Here, a self-powered SiC ultraviolet (UV) photodetector (PD) is constructed with wider applicability and higher commercialization potential. The great performance of the PD is realized by a remarkable photoinduced dynamic Schottky effect derived from the symbiotic modulation of Schottky and Ohmic contact. Using the pyro-phototronic effect that exists in the N-doped 4H-SiC single crystal PDs, a fast pyroelectric response time of 0.27 s is achieved, which is almost ten times shorter than that obtained from the steady-state signal under UV illumination. The maximal transient photoresponsivity reaches 9.12 nA mW-1 , which is ≈20% higher than the conventional photoelectric signal. Moreover, different regions of the 4H-SiC centimeter-scale chip output distinct signals under UV illumination, demonstrating efficient optical imaging and information transmission capabilities of this device. This work not only reveals the fundamental optoelectronic physics lying in this vital third-generation semiconductor, but also sheds light on its potential photosensing applications for large-scale commercialization.

Lattice relaxation effect in CsxMA(1-x)PbBr3 single crystal to enhance optoelectronic performance of perovskite photodetectors

Single crystal (SC) MAPbBr3 perovskite is regarded as a promising material to fabricate high-performance photodetectors (PDs) due to its impressive optoelectronic properties and good chemical stability. Cs+ doping has been proved to be an effective method to significantly improve the optoelectronic properties of MAPbBr3 SC. However, the intrinsic effect of Cs+ on the crystal structure is still unclear. Herein, we grew a series CsxMA(1-x)PbBr3 SCs. X-ray rocking curves (XRC) of CsxMA(1-x)PbBr3 SCs prove that appropriate Cs-doping concentration could reduce defect density effectively. X-ray photoelectron spectroscopy (XPS) measurements indicate that Cs-doping enhances the atoms interaction in CsxMA(1-x)PbBr3 lattice due to isoelectronic impurity effect. Single-crystal PDs were fabricated to compare the optoelectronic properties of MAPbBr3 SCs with different Cs-doping concentration, and the 2% Cs-doped CsxMA(1-x)PbBr3 PD shows the optimum performance. Density functional theory (DFT) calculations demonstrate that Cs-doping leads to lattice relaxation effect which is benefit to reduce trap density of CsxMA(1-x)PbBr3 SCs. The Pb-6p level of CsxMA(1-x)PbBr3 slightly shifts to lower energy region compared with MAPbBr3, resulting in the decrease of band gap of CsxMA(1-x)PbBr3.

Inorganic-Cation Pseudohalide 2D Cs2 Pb(SCN)2 Br2 Perovskite Single Crystal.

Most of the reported 2D Ruddlesden-Popper (RP) lead halide perovskites with the general formula of An +1 Bn X3 n +1 (n= 1, 2, …) comprise layered perovskites separated by A-site-substituted organic spacers. To date, only a small number of X-site-substituted RP perovskites have been reported. Herein, the first inorganic-cation pseudohalide 2D phase perovskite single crystal, Cs2 Pb(SCN)2 Br2 , is reported. It is synthesized by the antisolvent vapor-assisted crystallization (AVC) method at room temperature. It exhibits a standard single-layer (n= 1) Ruddlesden-Popper structure described in space group of Pmmn (#59) and has a small separation (d= 1.69 Å) between the perovskite layers. The SCN- anions are found to bend the 2D Pb(SCN)2 Br2 framework slightly into a kite-shaped octahedron, limiting the formation of a quasi-2D perovskite structure (n> 1).This 2D single crystal exhibits a reversible first-order phase transformation to 3D CsPbBr3 (Pm3m #221) at 450 K. It has a low exciton binding energy of 160 meV-one of the lowest for 2D perovskites (n= 1). A Cs2 Pb(SCN)2 Br2 -single-crystal photodetector is demonstrated with respectable responsivity of 8.46mA W-1 and detectivity of ≈1.2 × 1010 Jones at a low bias voltage of 0.5V.

Investigation and fabrication of Cadmium Telluride (CdTe) single crystal as a photodetector

Cadmium Telluride (CdTe) has a band gap of 1.5 eV at room temperature and is considered to be the most promising material for optoelectronic application. In the present work, we have selected the Bridgman grown CdTe single crystal and characterized it by Energy Dispersive Analysis of X-Rays (EDAX), Raman Spectroscopy, Photoluminescence Spectroscopy and Thermal Analysis techniques. EDAX has shown that there are no impurity elements present in CdTe sample and thereby proved its stoichiometry. We did Raman mapping up to the depth of 10 μm from the surface which has shown A1 mode at 121 cm−1 and TO mode at 140 cm−1. Raman spectra at low temperature from 80 K to 300 K is also studied on this sample. The photoluminescence spectra taken at room temperature with different excitation wavelength shows emission in different regions of the visible spectrum and IR region. TGA/DTA curves are recorded at three different heating rates from where we calculated various kinetic parameters. The I – V characteristics of prepared CdTe single crystal photodetector is measured at room temperature as well as low temperature up to 75 K. Pulse photoresponse at different biasing voltages at 50 mW/cm2 is recorded. Various parameters i.e. photocurrent, responsivity and detectivity from I – V characteristics has been determined. Photoconductivity measurements at different biasing voltage and at different polarizing angle is also carried out. The results obtained are explained in the paper in detail.