Quantum efficient fast UV photodetectors based on nanocrystalline Zn1-xPxO (x = 0.00, 0.03, 0.07) thin films deposited by pulsed laser deposition technique

Abstract Here, we demonstrate the effect of phosphorous doping concentration on the structural, electrical and optical properties of ZnO thin films deposited by pulse laser deposition technique. X-ray diffraction studies performed on the deposited films reveal the polycrystalline nature of films and confirm the deposition of ZnO films in wurtzite phase. However, the incorporation of phosphorous does not lead to originate new peak in XRD patterns of the doped films, negating the formation of new phase or the formation of P 2 O 5 phase of phosphorous. But this doping influences the peak positions of pure ZnO film which suggests that phosphorous taking the interstitially positions of Zn and compensates the incomplete bonds. The electrical conductivity of the deposited films is found to significantly increases with phosphorous doping. The prepared photo-devices have shown exceptional UV-photodetection ability under UVA light for fixed illumination intensity of 3.3 mW/cm 2 and varying intensities of ~ 0.367 to 3.3 mW/cm 2 . All the prepared devices have fast response and high sensitivity towards UV light. The response and recovery times for the deposited films are less than 200 ms, with sensitivity as high as ~ 85% at 3.3 mW/cm 2 illumination intensity for the device with 7 wt% doping of phosphorous. The high responsivity and detectivity as compared to reported literature, confirms the superior device performance and photo-characteristic of the prepared devices.