A5014265097- Perovskite Materials and Applications
- Conducting polymers and applications
- Quantum Dots Synthesis And Properties
- Organic Electronics and Photovoltaics
- ZnO doping and properties
- Chalcogenide Semiconductor Thin Films
- Photonic Crystals and Applications
- Thin-Film Transistor Technologies
- Copper-based nanomaterials and applications
- Organic Light-Emitting Diodes Research
- Gas Sensing Nanomaterials and Sensors
- Electronic and Structural Properties of Oxides
- Photonic and Optical Devices
- Advanced Photocatalysis Techniques
- Semiconductor materials and devices
- Advanced Memory and Neural Computing
- Solid-state spectroscopy and crystallography
- Ga2O3 and related materials
- Transition Metal Oxide Nanomaterials
- Nanowire Synthesis and Applications
- Molecular Junctions and Nanostructures
- Advanced Thermoelectric Materials and Devices
- Advanced biosensing and bioanalysis techniques
- Luminescence and Fluorescent Materials
- Nanopore and Nanochannel Transport Studies
Imperial College London
2015-2025
Imperial Valley College
2019-2023
Pohang University of Science and Technology
2023
Wake Forest University
2023
Chinese Academy of Sciences
2023
Cambridge Consultants (United Kingdom)
2023
Royal Society of Chemistry
2023
Georgia Institute of Technology
2023
University of London
2023
Institut de Recherche Interdisciplinaire de Grenoble
2023
This study reports the development of copper(I) thiocyanate (CuSCN) hole‐transport layers (HTLs) processed from aqueous ammonia as a novel alternative to conventional n‐alkyl sulfide solvents. Wide bandgap (3.4–3.9 eV) and ultrathin (3–5 nm) CuSCN are formed when CuSCN–ammine complex solution is spin‐cast in air annealed at 100 °C. X‐ray photoelectron spectroscopy confirms high compositional purity layers, while high‐resolution valence band spectra agree with first‐principles calculations....
Sequential layers of the high-k dielectric ZrO2 and electron transporting semiconductors ZnO Li-doped are deposited onto conductive indium tin oxide electrodes using spray pyrolysis. With these structures, thin-film transistors fabricated with operating voltages below 6 V maximum mobilities on order 85 cm2 V−1 s−1.
Copper thiocyanate (CuSCN) is introduced as a hole-injection/hole-transport layer (HIL/HTL) for solution-processed organic light-emitting diodes (OLEDs). The OLED devices reported here with CuSCN HIL/HTL perform significantly better than equivalent fabricated PEDOT:PSS HIL/HTL, and solution-processed, phosphorescent, small-molecule, green OLEDs maximum luminance ≥10 000 cd m(-2) , luminous efficiency ≤50 A(-1) power ≤55 lm W(-1) are demonstrated.
Zinc oxide (ZnO) is a widely utilized, versatile material implemented in diverse range of technological applications, particularly optoelectronic devices, where its inherent transparency, tunable electronic properties, and accessible nanostructures can be combined to confer superior device properties. ZnO complex with rich intricate defect chemistry, properties extremely sensitive processing methods conditions; consequently, surface modification using both inorganic organic species has been...
Formamidinium lead triiodide (FAPbI3 ) is attractive for photovoltaic devices due to its optimal bandgap at around 1.45 eV and improved thermal stability compared with methylammonium-based perovskites. Crystallization of phase-pure α-FAPbI3 conventionally requires high-temperature annealing 150 °C whilst the obtained metastable room temperature. Here, aerosol-assisted crystallization (AAC) reported, which converts yellow δ-FAPbI3 into black only 100 using precursor solutions containing...
An aqueous and carbon-free metal-oxide precursor route is used in combination with a UV irradiation-assisted low-temperature conversion method to fabricate low-voltage ZnO transistors electron mobilities exceeding 10 cm2/Vs at temperatures <180 °C. Because of its low temperature requirements the allows processing high-performance onto sensitive substrates such as plastic. As service our authors readers, this journal provides supporting information supplied by authors. Such materials are peer...
High mobility thin‐film transistor technologies that can be implemented using simple and inexpensive fabrication methods are in great demand because of their applicability a wide range emerging optoelectronics. Here, novel concept transistors is reported exploits the enhanced electron transport properties low‐dimensional polycrystalline heterojunctions quasi‐superlattices (QSLs) consisting alternating layers In 2 O 3 , Ga 3, ZnO grown by sequential spin casting different precursors air at...
A facile and low‐temperature (125 °C) solution‐processed Al‐doped ZnO (AZO) buffer layer functioning very effectively as electron accepting/hole blocking for a wide range of polymer:fullerene bulk heterojunction systems, yielding power conversion efficiency in excess 10% (8%) on glass (plastic) substrates is described. The ammonia‐treatment the aqueous AZO nanoparticle solution produces compact, crystalline, smooth thin films, which retain aluminum doping, eliminates/reduces native defects...
We report the application of ambient spray pyrolysis for deposition high-k polycrystalline Y2O3 and amorphous Al2O3 dielectrics their use in low-voltage ZnO thin-film transistors. The films are studied by means atomic force microscopy, UV-visible absorption spectroscopy, impedance field-effect measurements. transistors based on pyrolysed show low leakage currents, hysteresis-free operation with a maximum electron mobility 34 cm2/V s current on/off ratio order 105. This work is significant...
Here we report the investigation of controlled PbI<sub>2</sub> secondary phase formation in CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (MAPI) photovoltaics through post-deposition thermal annealing, identifying location active layer and its beneficial role on device performance.
Thin films of cuprous oxide (Cu2O) were grown using solution-based spray pyrolysis in ambient air and incorporated into hole-transporting thin-film transistors. The phase the was confirmed by X-ray diffraction measurements while optical band gap determined to be ∼2.57 eV from transmission measurements. Electrical characterization Cu2O performed bottom-gate, bottom-contact transistors based on SiO2 gate dielectric gold source-drain electrodes. As-prepared devices show clear p-channel...
We reveal the complex interplay between photoactive layer thickness and illumination intensity in perovskite solar cells, presenting design criteria for real-world concentrator applications.
Abstract Recombination via subgap trap states is considered a limiting factor in the development of organometal halide perovskite solar cells. Here, impact active layer crystallinity on accumulated charge and open‐circuit voltage ( V oc ) cells based methylammonium lead triiodide (CH 3 NH PbI , MAPI) demonstrated. It shown that MAPI can be systematically tailored by modulating stoichiometry precursor mix, where small quantities excess iodide (MAI) improve crystallinity, increasing device...
Indoor photovoltaics is one of the best sustainable and reliable energy source for low power consumption electronics such as rapidly growing Internet Things. Perovskite photovoltaic (PPV) cells with three benchmark device architectures – mesoporous PPV (mPPV) inverted (iPPV) alternative hole transporting layers (HTLs), carbon‐based (cPPV) are studied under a simulated indoor environment. The mPPV cell using typical Spiro‐OMeTAD HTL shows highest maximum density ( P max ) 19.9 μW cm −2 200...
AVA can passivate surface defect sites, resulting in enhanced resistivity to oxygen/light induced degradation.
Increasing the open-circuit voltage (Voc) is one of key strategies for further improvement efficiency perovskite solar cells. It requires fundamental understanding complex optoelectronic processes related to charge carrier generation, transport, extraction, and their loss mechanisms inside a device upon illumination. Herein, we report important origin Voc losses in methylammonium lead iodide (MAPI)-based cells, which results from undesirable positive (hole) accumulation at interface between...
This work highlights routes towards controlled substitutional doping of halide perovskites on the B-site to optimise their thermoelectric properties.
Phosphorene nanoribbons (PNRs) have been widely predicted to exhibit a range of superlative functional properties; however, because they only recently isolated, these properties are yet be shown translate improved performance in any application. PNRs show particular promise for optoelectronics, given their high exciton binding energies, tunable bandgaps, and ultrahigh hole mobilities. Here, we verify the theorized enhanced mobility both solar cells space-charge-limited-current devices,...
Abstract Lead halide perovskite and organic semiconductors are promising classes of materials for photodetector (PD) applications. State‐of‐the‐art PDs have performance metrics exceeding silicon in the visible. While offer bandgap tunability due to their chemical design with detection extended into near‐infrared (NIR), perovskites limited visible band first fraction NIR spectrum. In this work, perovskite–organic heterojunction (POH) absorption up 950 nm designed by dual contribution...
Abstract Inorganic semiconductors based on heavy pnictogen cations (Sb 3+ and Bi ) have gained significant attention as potential nontoxic stable alternatives to lead-halide perovskites for solar cell applications. A limitation of these novel materials, which is being increasingly commonly found, carrier localization, substantially reduces mobilities diffusion lengths. Herein, CuSbSe 2 investigated discovered delocalized free carriers, shown through optical pump terahertz probe spectroscopy...
A substantial increase in device performance and operational stability solution processed inverted bulk heterojunction (BHJ) organic photovoltaic devices (OPV) is demonstrated by introducing a zinc oxide (ZnO) interlayer between the electron collecting bottom electrode photoactive blend of poly(3-hexylthiophene) (P3HT) phenyl-C61-butyric acid methyl ester (PCBM). The structure morphology dense, planar ZnO layers were controlled either electro-deposition or spray pyrolysis techniques. Metal...
The growth of polycrystalline zinc oxide (ZnO) thin films by pulsed laser deposition (PLD) on indium tin (ITO) is reported. For the first time influence temperature over an extended range (50–650 °C) investigated ITO. We describe role optical and crystalline properties deposited films, 120–250 nm thickness. Additionally, effect background oxygen pressure Under all conditions highly textured c-axis oriented, transparent (>85%) low roughness (RMS < 10 nm) ZnO are formed. Growth temperatures...
Abstract Coplanar electrodes formed from asymmetric metals separated on the nanometre length scale are essential elements of nanoscale photonic and electronic devices. Existing fabrication methods typically involve electron-beam lithography—a technique that enables high fidelity patterning but suffers significant limitations in terms low throughput, poor scalability to large areas restrictive choice substrate electrode materials. Here, we describe a versatile method for rapid nanogap...
The use of ultrasonic spray pyrolysis is demonstrated for the growth polycrystalline, highly uniform indium oxide films at temperatures in range 200-300 °C air using an aqueous In(NO3)3 precursor solution. Electrical characterization as-deposited by field-effect measurements reveals a strong dependence electron mobility on deposition temperature. Transistors fabricated ∼250 exhibit optimum performance with maximum values 15-20 cm(2) V (-1) s(-1) and current on/off ratio excess 10(6)....