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

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

Effect of annealing temperature on electrical properties of hybrid ZnO/PTAA based heterojunction diode

A hybrid type heterojunction diode based on Zinc Oxide (ZnO) and Poly(triarylamine)(PTAA) thin films is fabricated using radio frequency and spin coating method. These are conducted in ambient condition. This research is done to investigate the effects of temperature on Schottky properties of ZnO/PTAA diode. PTAA is chemically dissolved in chloroform solution and deposited onto ZnO thin film at different spin rate of 1000 RPM and 2000 RPM. The fabricated diode is then annealed for 20 mins at a temperature ranging from 100 °C to 150 °C and surface morphological of fabricated diodes is observed using advance material microscope (HIROX). Investigation of current-voltage (I-V) is carried out in various bias voltage from -4.0 V to 4.0 V using Keithley 4-point prob. Investigation revealed that, diode show rectifying behaviour towards the increasing in annealing temperature. The highest ideality factor obtain is 1.62 at 120°C for 1000 RPM with barrier height of 0.745 eV and series resistance of 2.645 KΩ. The barrier height of diodes increases gradually with increasing in temperature while ideality factor decreases. Meanwhile, series resistance decreases significantly over increasing temperature from 4.28 KΩ to 0.412 KΩ for 1000 RPM and 4.166 KΩ to 0.063 KΩ for 2000 RPM. It clearly reveals that the temperature is highly correlated with the ideality factor of the device thus effecting the barrier height and series resistance in the devic

A hybrid inorganic-organic heterojunction device: structural morphology and electrical response

Organic-inorganic heterojunctions have a promising future due to their efficient optical and electrical properties, which make them technologically useful for optoelectronics applications. The aim of developing hybrid devices was to combine the significant advantages of each component that forms a heterojunction. It helps to decrease or overcome the drawbacks hindering to achieve the ideal behaviour of synergic effect that results in the development of new systems with new properties. Inorganic semiconductor materials offer a broader absorption of spectrum compared to the organic semiconductors. Their characteristic resemblance to green technology, optical and biocompatible properties presents improvements of response and sensitivity of electronic devices. Wide range resistance, high optical transparency in the visible light region and wide band-gap energy, enhances the application of oxide material for optoelectronics application. Combining such organics semiconductors with inorganics semiconductors of wide optical band-gap is a promising for optoelectronics applications and radio frequency identification (RFID) tags. Investigation of structural morphology and analysis of electrical response are presented to state the device performance based on a hetero-structure device configuration. Keywords: Hybrid inorganic, heterojunction, optical device, inorganic-organic semiconducto