A5101481570- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Perovskite Materials and Applications
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Integrated Circuits and Semiconductor Failure Analysis
- Quantum Dots Synthesis And Properties
- Semiconductor materials and interfaces
- Thin-Film Transistor Technologies
- Fault Detection and Control Systems
- ZnO doping and properties
- solar cell performance optimization
- Ga2O3 and related materials
- Advanced Semiconductor Detectors and Materials
- Chalcogenide Semiconductor Thin Films
- Silicon Nanostructures and Photoluminescence
- Infrared Target Detection Methodologies
- Calibration and Measurement Techniques
- Semiconductor Quantum Structures and Devices
- Machine Fault Diagnosis Techniques
- Advanced Control Systems Optimization
- Molecular Junctions and Nanostructures
- Fullerene Chemistry and Applications
- Photonic and Optical Devices
- Silicon and Solar Cell Technologies
University of California, Los Angeles
1989-2020
California NanoSystems Institute
2016-2020
National Taiwan University
2012-2013
National Cheng Kung University
1997-2007
Abstract Despite significant development recently, improving the power conversion efficiency of organic photovoltaics (OPVs) is still an ongoing challenge to overcome. One prerequisites achieving this goal enable efficient charge separation and small voltage losses at same time. In work, a facile synthetic strategy reported, where optoelectronic properties are delicately tuned by introduction electron-deficient-core-based fused structure into non-fullerene acceptors. Both devices exhibited...
Perovskite/CIGS tandem cells Tandem solar can boost efficiency by using more of the available spectrum. Han et al. fabricated a two-terminal cell with an inorganicorganic hybrid perovskite top layer and Cu(In,Ga)Se 2 (CIGS) bottom layer. Control roughness CIGS surface use heavily doped organic hole transport were crucial to achieve 22.4% power conversion efficiency. The unencapsulated maintained almost 90% their after 500 hours operation under ambient conditions. Science , this issue p. 904
Incorporating narrow-bandgap near-infrared absorbers as the third component in a donor/acceptor binary blend is new strategy to improve power conversion efficiency (PCE) of organic photovoltaics (OPV). However, there are two main restrictions: potential charge recombination narrow-gap material and miscompatibility between each component. The optimized design employ (structurally similar donor or acceptor) with lowest unoccupied molecular orbital (LUMO) energy level acceptor highest occupied...
Abstract Recently, a new type of active layer with ternary system has been developed to further enhance the performance binary organic photovoltaics (OPV). In OPV, almost all layers are formed by simple blend in solution, which eventually leads disordered bulk heterojunction (BHJ) structure after spin‐coating process. There two main restrictions this BHJ obtain higher OPV. One is isolated second donor or acceptor domains. The other invalid metal–semiconductor contact. Herein, concept and...
Solvent additive processing has become the most effective method to tune nanostructure of donor–acceptor (D–A) type copolymer/fullerene bulk heterojunctions (BHJs) solar cells for improving power conversion efficiencies. However, date qualitative microscopic observations reveal discrepant results on effects solvent additives. Here, we present quantitative evolution bi-hierarchical D–A copolymers and fullerenes by employing grazing-incidence small/wide angle X-ray scattering (GISAXS/GIWAXS)...
Abstract Herein, a 2D SnS 2 electron transporting layer is reported via self‐assembly stacking deposition for highly efficient planar perovskite solar cells, achieving over 20% power conversion efficiency under AM 1.5 G 100 mW cm −2 light illumination. To the best of authors' knowledge, this represents highest that has so far been cells using layer. The large‐scaled multilayer sheet structure triggers heterogeneous nucleation precursor film. intermolecular Pb⋅⋅⋅S interactions between and...
The development of low bandgap conducting polymers has made bulk heterojunction solar cells a viable cost renewable energy source. high boiling point 1,8-diiodooctane (DIO) is usually used to control the morphology active layer consisting polymer and PCBM, so that power conversion cell can be achieved. We report here an alternative approach using nonvolatile, crystalline P3HT as effective agent. A model system PCPDTBT/PC61BM was selected for this study. change optoelectronic properties with...
The morphology, photophysics, and device performance of solar cells based on the low bandgap polymer poly[[2,6′‐4,8‐di(5‐ethylhexylthienyl)benzo[1,2‐ b ;3,3‐ ]dithiophene]3‐fluoro‐2[(2‐ethylhexyl)carbonyl]thieno[3,4‐ ]thiophenediyl (PBDTTT‐EFT) (also known as PTB7‐Th) blended with different fullerene acceptors: Phenyl‐C 61 ‐butyric acid methyl ester (PC BM), phenyl‐C 71 or indene‐C 60 bisadduct (ICBA) are correlated. Compared to PC BM‐based – which achieve a power conversion efficiency (PCE)...
Abstract Solution‐processed indium‐gallium‐zinc oxide (IGZO) thin film transistors (TFTs) have become well known in recent decades for their promising commercial potential. However, the unsatisfactory performance of small‐sized IGZO TFTs is limiting applicability. To address this issue, work introduces an interface engineering method bi‐functional acid modification to regulate interfaces between electrodes and channels TFTs. This increases oxygen vacancy concentration reduces surface...
The electron transport layer (ETL) plays an important role in determining the device efficiency of organic solar cells (OSCs). A rational design ETL for OSCs targets high charge extraction and induction optimized active morphology. In this Letter, a mobility In2O3 synthesized via solution-processed combustion reaction is successfully used as universal photovoltaic device. With modification thin polyethylenimine ethoxylated (PEIE), based on crystalline outperforms its counterpart, ZnO, both...
The application of tandem structure that integrates multiple subcells into one device is a promising way to realize high efficiency organic solar cells. However, current-matching among different remains as the main challenge for photovoltaics. Here, we provide facile approach achieve good current matching via engineering chemical composition non-fullerene ternary blend subcells. For front subcell, PDBT-T1:TPH-Se:ITIC selected due its thermal stability. amorphous nature TPH-Se can...
Isoindigo based conducting polymers have attracted extensive interest for polymer solar cell application since isoindigo is a green material and renewable from plants. We synthesized four soluble low band gap (PCI) with cyclopentadithiophene (CPDT) as the donor unit (I) acceptor unit, decorated two kinds of alkyl side chains, octyl (8) 2-ethylhexyl (e), via Stille cross-coupling reaction denoted PC8I8, PC8Ie, PCeI8 PCeIe. By changing chain copolymers linear (PC8I8) to branched (PCeIe), λmax...
Organic tandem solar cells have two sub‐cells vertically connected via a tunnel junction (or interconnecting layer, ICL), which the ICL plays critical role of determining performance cell. In this manuscript, we report new design consisting zirconium (IV) acetylacetonate (Zr‐Acac) as electron transport layer. The Zr‐Acac has suitable work function to pin Fermi‐level and hence, can effectively behave charge recombination for device. Comparing reference device ZnO ETL enhance efficiency by...
In light of the importance and challenges inherent in realizing a wearable healthcare platform for simultaneously recognizing, preventing, treating diseases while tracking vital signs, development simple customized functional devices has been required. Here, we suggest new approach making stretchable waveguide which can be combined with integrated devices, such as organic photodetectors (PDs) nanowire-based heaters, multifunctional monitoring. Controlling reflection condition medium gave...
Experimental results are presented for noise voltage, responsivity, and specific detectivity (D*) the long wavelength infrared (IR) HgCdTe photoconductive detectors. Hg/sub 0.8/Cd/sub 0.2/Te detectors passivated with ZnS/photo-enhanced native oxide have an improved spectral density D* than only ZnS. The low frequency 1/f charges were measured a photo detector, as function of bias at 77 K, effective surface trap determined from 1 Hz. It was found that densities stacked sample ZnS close to...
Nonfullerene acceptors have recently emerged as promising candidates for organic photovoltaics (OPVs) owing to their superior optoelectronic properties. However, the varied lowest unoccupied molecular orbital (LUMO) levels of pose difficulty in aligning energy with existing electron transporting layers (ETLs). The authors propose here a facile design ETL tunable work function by simply varying annealing temperature titanium diisopropoxide bis(acetylacetonate) (TIAA) change structure complex....