A5013041727- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Conducting polymers and applications
- Quantum Dots Synthesis And Properties
- Organic Electronics and Photovoltaics
- Solid-state spectroscopy and crystallography
- solar cell performance optimization
- Transition Metal Oxide Nanomaterials
- Diamond and Carbon-based Materials Research
- Ion-surface interactions and analysis
- Metal and Thin Film Mechanics
- Advanced battery technologies research
- Analytical Chemistry and Sensors
National Renewable Energy Laboratory
2019-2021
Stanford University
2018-2021
University of Colorado Boulder
2019-2021
CoorsTek (United States)
2020
Stanford Medicine
2018
Tuning band gaps with three halides Tandem solar cells can boost cell efficiency by using two active layers to absorb the spectrum more completely, provided that are current-matched. Inorganic-organic perovskites tuned appropriate wide gap (∼1.7 electron volts) as top contained iodine and bromine or chlorine have short carrier diffusion lengths undergo photo-induced phase segregation. Xu et al. now report a method for incorporating chloride allows fabrication of stable triple-halide 1.67...
Glass and edge seal encapsulation of a perovskite solar cell to enable stability through damp heat thermal cycling tests.
Metal-contact-induced degradation and escape of volatile species from perovskite solar cells necessitate excellent diffusion barrier layers. We show that metal-induced limits thermal stability in several chemistries with Au, Cu, Ag gridlines even when the metal is separated by a layer indium tin oxide (ITO). Channels sputtered ITO align grain boundaries are pathways for halide into or out perovskite. Planarizing morphology spin-cast organic charge-transport results subsequently deposited...
We report the fabrication of monolithic all-perovskite tandem solar cells with a stabilized power conversion efficiency 19.1% and demonstrate improved thermal, atmospheric, operational stability tin–lead perovskite (FA<sub>0.75</sub>Cs<sub>0.25</sub>Sn<sub>0.5</sub>Pb<sub>0.5</sub>I<sub>3</sub>) used as low gap absorber.
Low-bandgap Sn/Pb ABX3 perovskites have reached photovoltaic power conversion efficiencies >20%, but they usually poor stability due to the common use of acidic poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) hole transport layers and A-site cation compositions containing methylammonium (MA). Here, we develop a process enable high-quality MA-free perovskite films grown using gas quenching instead conventional antisolvents, which provides improved control film growth...
Temperature coefficients for maximum power (TPCE), open circuit voltage (VOC), and short current (JSC) are standard specifications included in data sheets any commercially available photovoltaic module. To date, there has been little work on determining the TPCE perovskite photovoltaics (PV). We fabricate solar cells with a of -0.08 rel %/°C then disentangle temperature-dependent effects absorber, contact layers, interfaces by comparing different device architectures using drift-diffusion...
Abstract Partial shading of a solar module can induce set cells within the to operate under reverse bias. Studies have shown that metal halide perovskite with wide variety compositions and contacts exhibit interesting behavior in bias includes both reversible performance loss non‐reversible degradation. In this paper, an advanced drift‐diffusion approach incorporating electrochemical term explain short‐circuit, open circuit fill factor losses are experimentally measured after prolonged is...
Abstract Metal‐halide perovskites show promise as highly efficient solar cells, light‐emitting diodes, and other optoelectronic devices. Ensuring long‐term stability is now a major priority. In this study, an ultrathin (2 nm) layer of polyethylenimine ethoxylated (PEIE) used to functionalize the surface C 60 for subsequent deposition atomic (ALD) SnO 2 , commonly electron contact bilayer p–i–n The enhanced nucleation results in more continuous initial ALD that exhibits superior barrier...
Abstract The excellent optoelectronic properties demonstrated by hybrid organic/inorganic metal halide perovskites are all predicated on precisely controlling the exact nucleation and crystallization dynamics that occur during film formation. In general, high‐performance thin films obtained a method commonly called solvent engineering (or antisolvent quench) processing. removes excess solvent, but importantly leaves behind forms chemical adducts with lead‐halide precursor salts. These...
This perspective shines light on alternative module designs, discussing their pros & cons.
Excellent contact passivation and selectivity are prerequisites to realize the full potential of high‐material‐quality perovskite solar cells, first maximize internal voltage (or quasi‐Fermi‐level separation) iV within absorber, then translate this high into a external V . Experimental quantification is, thus, key improving device performance. Here, open‐circuit measurements oc , combined with surface photovoltage measurements, used systematically quantify passivation—using as metric—and...
SPV measurement through the Kelvin probe method is described. Silicon heterojunction structures show maximum of 700 V. Measurement on perovskite structures, and results suggest adding BCP with C60 enhances selectivity electron contact. Furthermore, PTAA PTAA/PFN have similar but NiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> poorly selective. an easy way to provide a relative comparison between various cell contact layers determine...
We describe the development of novel perovskite active layers and sputter-buffer for perovskite-silicon tandems with efficiencies surpassing 25% that pass a variety IEC standard stability tests.
We found Br/I mixed perovskite with high fraction of Cs can steadily incorporate Cl-based to tune the bandgap. The resulting films exhibit significant improvement in mobility and lifetime photocarriers. In 1.67eV wide-bandgap top cells optimized for perovskite/Si tandems, we achieved a great reducing voltage-of-open-circuit (VOC) deficit from 0.57eV 0.45eV, which is among best Si tandems reported so far. stabilized PCE improved 17-18% 20%, featured VOC (1.22V) FF (83%). This advance holds...
Hybrid organic-inorganic lead halide perovskite solar cells have made rapid advancements in efficiency, approaching and overtaking those of other thin-film technologies. Before commercialization can be achieved, however, the stability must improved. While moisture exposure mitigated through careful encapsulation, thermal cell, with respect to both intrinsic degradation absorber material extrinsic reactions layers, is critical. We evaluate semitransparent FA0.83Cs0.17Pb(I0.83Br0.17)3 MAPbI3...
Vertical glass facade buildings, such as skyscrapers, have significant potential for generating electricity using solar window technologies, SwitchGlaze, a switchable photovoltaic window. This contains perovskite layer that absorbs visible, infrared, and UV light. To commercialize this other perovksite cells, it is essential to optimize scalable production process, electrodeposition, which can controllably fabricate stable transport layers. technique then be used back contact devices...