Effect of doped TiO2 film as electron transport layer for inverted organic solar cell

Nanocrystalline TiO2 and Sn-doped TiO2 thin films were prepared by sol–gel spin coating method. The crystallinity and anatase phase of TiO2 and Sn-doped TiO2 were confirmed from X-ray diffraction analysis. The EDAX analysis also confirmed the presence of tin, oxygen and titania elements. By fabricating an inverted organic solar cell with device configuration of ITO/Sn-doped TiO2/active layer/MoO3/Al, power conversion efficiency (PCE) of the Sn-doped TiO2 was observed to be 3.08% compared to the TiO2 based solar cell of 2.64%

Marigold flower like structured Cu2NiSnS4 electrode for high energy asymmetric solid state supercapacitors

The growth in energy devices and the role of supercapacitors are increasingly important in today’s world. Designing an electrode material for supercapacitors using metals that have high performance, superior structure, are eco-friendly, inexpensive and highly abundant is essentially required for commercialization. In this point of view, quaternary chalcogenide Cu2NiSnS4 with fascinating marigold flower like microstructured electrodes are synthesized using different concentrations of citric acid (0, 0.05 M, 0.1 M and 0.2 M) by employing solvothermal method. The electrode materials physicochemical characteristics are deliberated in detail using the basic characterization techniques. The electrochemical studies revealed better electrochemical performances, in particular, [email protected] M-CA electrode revealed high 1029 F/g specific capacitance at 0.5 A/g current density. Further, it retained 78.65% capacity over 5000 cycles. To prove the practical applicability, a full-cell asymmetric solid-state device is fabricated, and it delivered 41.25 Wh/Kg and 750 Wh/Kg energy and power density at 0.5 A/g. The optimum citric acid added Cu2NiSnS4 electrode is shown to be a promising candidate for supercapacitor applications

Highly efficient perovskite solar cells with Ba(OH)2 interface modification of mesoporous TiO2 electron transport layer

Outstanding photovoltaic performances together with some advantageous fabrication methods are the driving forces for recent research in perovskite solar devices. Interfacial engineering greatly influences the overall performance of the organic–inorganic perovskite solar cell as it alters energy band alignment, carrier recombination, and charge extraction/transport. In this work, Ba(OH)2 was spun between the meso-TiO2 electron transport and organic–inorganic perovskite absorber layers to engineer the interface and enhance the photovoltaic performance. Ba(OH)2 modification shifted the conduction band of meso-TiO2 upward such that better alignment with perovskite energy level, reduced carrier recombination, enhanced optical absorption, and electron transportation were observed. These enhancements led to paramount power conversion efficiency (PCE) of 17.53% for optimum Ba(OH)2 concentration of 5 mg/mL spun on meso-TiO2 but poorer PCE of 16.08% for the devices without interfacial treatment. Through this study, we demonstrated the use of interface modification as a straightforward yet powerful approach to enhance performances of conventional perovskite solar cells.Ministry of Education (MOE)Accepted versionThe research is supported by an AcRF Tier1 Grant (MOE2017-T1-002-142) from the Singapore Ministry of Education. We would thank Prof. Subodh Mhaisalkar, Executive Director of Energy Research Institute @ NTU (ERI@N) for supporting this work

Improved photovoltaic performance of triple-cation mixed-halide perovskite solar cells with binary trivalent metals incorporated into the titanium dioxide electron transport layer

Among the next-generation photovoltaic technologies, perovskite solar cells have attracted significant attention and interest. In addition to the perovskite absorber component, the adjacent layers within the stack play decisive roles in the stability and overall power conversion efficiency (PCE) of a device. In this study, we demonstrated the use of a solution-processed aluminium indium (AlIn)-TiO2 compact layer as a highly effective electron transport layer (ETL) to achieve outstanding performance of perovskite solar cells; our results showed that the incorporation of AlIn into the TiO2 layer allowed better energy band alignment of the ETL-perovskite interface, improved the transparency, and enhanced the conductivity as compared to the case of pristine TiO2. Via co-doping these trivalent metals, an enhancement in voltage, current density, and even fill factor was observed. In addition, the results obtained from electrochemical impedance spectroscopy (EIS) revealed that the AlIn-TiO2-based device exhibited larger recombination resistance, which significantly benefited the performance of the devices. As a result, the optimized AlIn-TiO2 ETL device attained the surpassing PCE of 19% as compared to the pristine TiO2 solar device having the PCE of 16.67%.Ministry of Education (MOE)Accepted versionWe would like to acknowledge the financial support received from the Singapore Ministry of Education through AcRF Tier1 grant MOE2017-T1-002-142. We thank Prof. Subodh Mhaisalkar, Executive Director of Energy Research Institute@NTU (ERI@N) for supporting this work. The authors acknowledge the Facility for Analysis, Characterization, Testing and Simulation (FACTS), Nanyang Technological University, Singapore, for the use of XPS/UPS facilities