Byungha Shin

ABSTRACT Using vacuum process, we fabricated Cu 2 ZnSnS 4 solar cells with 8.4% efficiency, a number independently certified by an external, accredited laboratory. This is the highest efficiency reported for pure sulfide Cu 2 ZnSnS 4 prepared by any method. Consistent with literature, the optimal composition is Cu‐poor and Zn‐rich despite the precipitation of secondary phases (e.g., ZnS). Despite a very thin absorber thickness (~600 nm), a reasonably good short‐circuit current was obtained. Time

Maximizing the power conversion efficiency (PCE) of perovskite/silicon tandem solar cells that can exceed the Shockley-Queisser single-cell limit requires a high-performing, stable perovskite top cell with a wide bandgap. We developed a stable perovskite solar cell with a bandgap of ~1.7 electron volts that retained more than 80% of its initial PCE of 20.7% after 1000 hours of continuous illumination. Anion engineering of phenethylammonium-based two-dimensional (2D) additives was critical for co

peer reviewed

An ultrahigh performance MoS2 photodetector with high photoresponsivity (1.94 × 10(6) A W(-1) ) and detectivity (1.29 × 10(12) Jones) under 520 nm and 4.63 pW laser exposure is demonstrated. This photodetector is based on a methyl-ammonium lead halide perovskite/MoS2 hybrid structure with (3-aminopropyl)triethoxysilane doping. The performance degradation caused by moisture is also minimized down to 20% by adopting a new encapsulation bilayer of octadecyltrichlorosilane/polymethyl methacrylate.

Organic-inorganic hybrid perovskites attract enormous research interest for next generation solar energy harvest. Synergistic crystalline structures comprising organic and inorganic components enable solution processing of perovskite films. A reliable crystallization method for perovskites, compatible with fast continuous process over large-area flexible substrates, is crucial for high performance solar cell production. Here, we present laser crystallization of hybrid perovskite solar cells usin

The Material properties of BiVO₄ are modified <italic>via</italic> coupling with a SnO₂ buffer layer inserted between BiVO₄ and a FTO substrate.

Abstract Using in situ electrical biasing transmission electron microscopy, structural and chemical modification to n–i–p‐type MAPbI 3 solar cells are examined with a TiO 2 electron‐transporting layer caused by bias in the absence of other stimuli known to affect the physical integrity of MAPbI 3 such as moisture, oxygen, light, and thermal stress. Electron energy loss spectroscopy (EELS) measurements reveal that oxygen ions are released from the TiO 2 and migrate into the MAPbI 3 under a forwar

We have studied the temperature dependent kinetics of MoSe2 formation between molybdenum and Cu2ZnSnSe4 (CZTSe) films during annealing in the presence of Se. CZTSe is an emerging light-absorbing material for thin film solar cell applications, and thermal treatment of this layer constitutes a critical part of the device processing. The formation of MoSe2 in this system is modeled using a three step mechanism—diffusion of Se through CZTSe, diffusion of Se through MoSe2, and reaction between Se and

Abstract Redox enzymes catalyze fascinating chemical reactions with excellent regio- and stereo-specificity. Nicotinamide adenine dinucleotide cofactor is essential in numerous redox biocatalytic reactions and needs to be regenerated because it is consumed as an equivalent during the enzymatic turnover. Here we report on unbiased photoelectrochemical tandem assembly of a photoanode (FeOOH/BiVO 4 ) and a perovskite photovoltaic to provide sufficient potential for cofactor-dependent biocatalytic r

Abstract The role of Cl in halide hybrid perovskites CH 3 NH 3 PbI 3 (Cl) (MAPbI 3 (Cl)) on the augmentation of grain size is still unclear although many reports have referred to these phenomena. Herein, we synthesized MAPbI 3 (Cl) perovskite films by using excess MACl-containing precursors, which exhibited approximately an order of magnitude larger grain size with higher &lt;110&gt;-preferred orientation compared with that from stoichiometric precursors. Comprehensive mechanisms for the large g

Abstract This study reports on substantial improvement of the open‐circuit voltage ( V oc ) of Cu 2 ZnSnSe 4 (CZTSe) thin film solar cells by applying a passivation strategy to both the top and bottom interfaces of the CZTSe absorber, which involves insertion of a thin dielectric layer between the CZTSe and the surrounding layers. The study also presents in‐depth material characterizations using transmission electron microscopy, energy dispersive X‐ray spectroscopy, low‐temperature photoluminesc

The solution process is the most widely used method to prepare perovskite absorbers for high performance solar cells due to its ease for fabrication and low capital cost. However, an insufficient level of reproducibility of the solution process is often a concern. Complex precursor solution chemistry is likely one of the main reasons for the reproducibility issue. Here we report the effects of triple cation lead mixed-halide perovskite precursor solution aging on the quality of the resulting fil

Recently, the trend in inverted hybrid perovskite solar cells (PVSCs) has been to utilize NiO x as hole transport layers. However, the majority of reported solution-processed NiO x films require a high-temperature thermal annealing process, which is unfavorable for large-scale manufacturing and suffers from lack of uniformity. We report, for the first time, e-beam evaporation as a low-temperature vacuum process for the deposition of NiO x hole transport layers for PVSCs. Device characterization