A5020764720- Perovskite Materials and Applications
- Conducting polymers and applications
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Solid-state spectroscopy and crystallography
- Organic Light-Emitting Diodes Research
- Electronic and Structural Properties of Oxides
- Transition Metal Oxide Nanomaterials
- Technostress in Professional Settings
- 2D Materials and Applications
- Layered Double Hydroxides Synthesis and Applications
- Optical properties and cooling technologies in crystalline materials
- Organic Electronics and Photovoltaics
- MXene and MAX Phase Materials
- Gas Sensing Nanomaterials and Sensors
- Ferroelectric and Negative Capacitance Devices
- Advancements in Solid Oxide Fuel Cells
Applied Physical Sciences (United States)
2017-2023
University of North Carolina at Chapel Hill
2017-2023
Communities In Schools of Orange County
2019-2020
The power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) are already higher than that other thin film technologies, but laboratory cell-fabrication methods not scalable. Here, we report an additive strategy to enhance the efficiency and stability PSCs made by scalable blading. Blade-coated incorporating bilateral alkylamine (BAA) additives achieve PCEs 21.5 (aperture, 0.08 cm2) 20.0% 1.1 cm2), with a record-small open-circuit voltage deficit 0.35 V under AM1.5G illumination....
Abstract The efficiencies of green and red perovskite light-emitting diodes (PeLEDs) have been increased close to their theoretical upper limit, while the efficiency blue PeLEDs is lagging far behind. Here we report enhancing sky-blue by overcoming a major hurdle low photoluminescence quantum in wide-bandgap perovskites. Blending phenylethylammonium chloride into cesium lead halide perovskites yields mixture two-dimensional three-dimensional perovskites, which enhances from 1.1% 19.8%....
Abstract Developing multijunction perovskite solar cells (PSCs) is an attractive route to boost PSC efficiencies above the single-junction Shockley-Queisser limit. However, commonly used tin-based narrow-bandgap perovskites have shorter carrier diffusion lengths and lower absorption coefficient than lead-based perovskites, limiting efficiency of perovskite-perovskite tandem cells. In this work, we discover that charge collection in PSCs limited by a short length electrons. Adding 0.03 molar...
State-of-the-art, high-performance perovskite solar cells (PSCs) contain a large amount of iodine to realize smaller bandgaps. However, the presence numerous vacancies at surface film formed by their evaporation during thermal annealing process has been broadly shown induce deep-level defects, incur nonradiative charge recombination, and photocurrent hysteresis, all which limit efficiency stability PSCs. In this work, modifying defective films with cadmium iodide (CdI2) effectively reduces...
Ion migration in a three-dimensional (3D) perovskite is the source of many unique phenomena such as photocurrent hysteresis and giant switchable photovoltaic effect can also accelerate degradation perovskite-based electronic devices. Here we report observation suppressed ion along in-plane direction layered perovskites by studying conductivity single-crystal at varied temperatures. Large-area thin single crystals are synthesized space-confined method. The absence these be explained an...
Abstract Perovskite materials are good candidates for flexible photovoltaic applications due to their strong absorption and low‐temperature processing, but efficient perovskite modules have not yet been realized. Here, a record efficiency solar module is demonstrated by blade coating high‐quality films on Corning Willow Glass using additive engineering. Ammonium chloride (NH 4 Cl) added into the precursor solution retard nucleation which prevents voids formation at interface of glass. The...
Identifying the origin of intrinsic instability for organic-inorganic halide perovskites (OIHPs) is crucial their application in electronic devices, including solar cells, photodetectors, radiation detectors, and light-emitting diodes, as efficiencies or sensitivities have already been demonstrated to be competitive with commercial available devices. Here we show that free charges OIHPs, whether generated by incident light current-injection from electrodes, can reduce stability, while...
Tailoring the doping of semiconductors in heterojunction solar cells shows tremendous success enhancing performance many types inorganic cells, while it is found challenging perovskite because difficulty perovskites a controllable way. Here, small molecule 4,4',4″,4″'-(pyrazine-2,3,5,6-tetrayl) tetrakis (N,N-bis(4-methoxyphenyl) aniline) (PT-TPA) which can effectively p-dope surface FAx MA1-x PbI3 (FA: HC(NH2 )2 ; MA: CH3 NH3 ) films reported. The intermolecular charge transfer property...
Currently, blade-coated perovskite solar cells (PSCs) with high power conversion efficiencies (PCEs), that is, greater than 20%, normally employ methylammonium lead tri-iodide a sub-optimal bandgap. Alloyed perovskites formamidinium (FA) cation have narrower bandgap and thus enhance device photocurrent. However, FA-alloyed show low phase stability moisture sensitivity. Here, it is reported incorporating 0.83 molar percent organic halide salts (OHs) into inks enables phase-pure, highly...
With power conversion efficiencies now reaching 24.2%, the major factor limiting efficient electricity generation using perovskite solar cells (PSCs) is their long-term stability. In particular, PSCs have demonstrated rapid degradation under illumination, driving mechanism of which yet to be understood. It shown that elevated device temperature coupled with excess charge carriers due constant illumination dominant force in encapsulated illumination. Cooling 20 °C and operating at maximum...
Metal halide perovskites have arisen as a new family of semiconductors for radiation detectors due to their high stopping power, large and balanced electron–hole mobility-lifetime (<italic>μτ</italic>) product, tunable bandgap.
Layered perovskites have been employed for various optoelectronic devices including solar cells and light-emitting diodes improved stability, which need exciton transport along both the in-plane out-of-plane directions. However, it is not clear yet what determines direction, important to understand its impact toward electronic devices. Here, by employing steady-state transient photoluminescence mapping, found that diffusivities in layered are sensitive number of layers organic cations. Apart...
Abstract Ferroelasticity represents material domains possessing spontaneous strain that can be switched by external stress. Three-dimensional perovskites like methylammonium lead iodide are determined to ferroelastic. Layered have been applied in optoelectronic devices with outstanding performance. However, the understanding of lattice and ferroelasticity layered is still lacking. Here, using in-situ observation switching perovskite single crystals under strain, we discover evidence layer...
Abstract Charge transport layers play an important role in determining the power conversion efficiencies (PCEs) of perovskite solar cells (PSCs). However, it has proven challenging to produce thin and compact charge via solution processing techniques. Herein, a hot substrate deposition method capable improving morphology high‐coverage hole‐transport (HTLs) electron‐transport (ETLs) is reported. PSC devices using HTLs deposited on show improvement open‐circuit voltage ( V oc ) from 1.041...
Tantalum nitride (Ta3N5) has gained significant attention as a potential photoanode material, yet it been challenged by material quality issues. Defect-induced trap states are detrimental to the performance of any semiconductor material. Beyond influencing Ta3N5 films, defects can also accelerate degradation in water during desired electrochemical applications. Defect passivation provided an enormous boost development many materials but is currently its infancy for Ta3N5. This part due lack...
In article number 1701659, Jinsong Huang, Jiarong Lian, and co-workers propose a simple hot-substrate deposition method to prepare thin film with higher coverage improved uniformity. The hot substrate improves the adhesion of solvent on speeds its drying process avoid aggregation upmost molecules, so that both reduced current leakage series resistance are simultaneously realized in perovskite solar cells.