Low Leakage Current by Solution Processed PTAA-ZnO Transparent Hybrid Hetero-Junction Device

• Main Authors: Bablu K. Ghosh, Abdul I. A. Rani, Khairul A. Mohamad, Ismail Saad
• Format: Article
• Language: English; English
• Published: 2020
• Subjects: T Technology (General); TA Engineering (General). Civil engineering (General)
• Online Access: https://eprints.ums.edu.my/id/eprint/25949/1/Low%20Leakage%20Current%20by%20Solution%20Processed%20PTAA-ZnO%20Transparent%20Hybrid%20Hetero-Junction%20Device.pdf; https://eprints.ums.edu.my/id/eprint/25949/2/Low%20Leakage%20Current%20by%20Solution%20Processed%20PTAA-ZnO%20Transparent%20Hybrid%20Hetero-Junction%20Device1.pdf; https://eprints.ums.edu.my/id/eprint/25949/; https://doi.org/10.1007/s13391-020-00235-y

In this work solution processed novel poly-triarylamine (PTAA) organic p-type active layer on inorganic n-ZnO device transparency and electrical properties are investigated under illumination. Low cost organic-inorganic transparent hybrid hetero-junction (HHJ) is a promising candidate for next-generation photovoltaic applications. Greater band gap organic material window layer while inorganic material’s higher thermal stability as HHJ is suitable for detection and photovoltaic applications. However, hetero-interface defects associated leakage current is the key issue of undermining large-area device electrical performance. Hetero-interface defect associated carriers optical absorption limits transparency whereas leakage current density is reliant on physical property and band barrier effect. It is demanded to investigate hetero-device physical stuff and band barrier effect on electrical properties. Novel PTAA is deposited on RF-sputtered inorganic n-ZnO/ITO/glass substrate by spin-coating method. 100 and 60 nm PTAA thin films are deposited with 1,000 and 2,000 revolution per minute (rpm) growth sequence, respectively. PTAA as a transparent p-emitter is shown to absorb incident light beyond visible band, thereby it has promoted excitonic effect. Device I−V characterization carried out at different annealing temperatures and applied voltage. Suitable annealing condition leakage current is shown to reduce nearly 10-4A/cm2 and at higher applied field the greater rectifying I(+)/I(-) ratio is realized. Grain size is shown to increase with annealing effect however; leakage current is remained almost independent of grain size.