Preparation of low cost n-ZnO/MgO/p-Si heterojunction photodetector by laser ablation in liquid and spray pyrolysis

• Published in: Materials research express 2018-05, Vol.5 (5), p.55018
• Main Authors: Ismail, Raid A, Khashan, Khawla S, Jawad, Muslim F, Mousa, Ali M, Mahdi, Farah
• Format: Article
• Language: English
• Subjects: laser ablation; MgO; nanoflowers; photodetector; water; ZnO film
• ISSN: 2053-1591; 2053-1591
• DOI: 10.1088/2053-1591/aac24e

In this study, low cost ZnO/Si and ZnO/MgO/Si heterojunction (HJ) photodetectors were fabricated using laser ablation and spray Pyrolysis techniques. MgO nanofibers were synthesized by laser ablation of Mg target in distilled water. Also; the ZnO films were prepared by spray pyrolysis technique. The optical and structural properties of nanostructured MgO were investigated using XRD, SEM and FT-IR. The XRD results showed that the MgO was polycrystalline with cubic structure. SEM investigation confirmed the formation of MgO nanofibers and sub-microparticles. The optical energy gaps of MgO and ZnO were calculated and found to be 5.7 eV and 3.3 eV, respectively. For the electrical properties; responsivity, quantum efficiency, specific detectivity, and speed of response of the photodetector were measured and found to enhance after the insertion of nanostructured MgO film. The Photoresponse results at 3 V reverse bias showed that the maximum responsivity of ZnO/Si and ZnO/MgO/Si photodetectors were 185 and 331 mAW−1 at 500 nm, respectively. The specific detectivity of ZnO/MgO/Si Photodetector was higher than that of ZnO/Si.