Location-Optoelectronic Property Correlation in ZnO:Al Thin Film by RF Magnetron Sputtering and Its Photovoltaic Application

In this study, a radio-frequency magnetron sputter system was used to deposit Al2O3 doped ZnO (AZO) thin films at room temperature, and the soda lime glass (SLG) substrates were placed at different zones relative to the center of the sample holder under the target. The samples were then analyzed using an X-ray diffractometer, Hall-effect measurement system, UV-visible spectrophotometer, and X-ray photoelectron spectroscopy. It was found that the electrical, structural, and optical properties of AZO films strongly depend on the target racetrack. The AZO thin film grown at a location outside the racetrack not only has the most suitable figure of merit for transparent conductive films, but also retains the least residual stress, which makes it the most suitable candidate for use as a CZTSe transparent conductive layer. When applied to CZTSe solar cells, the photoelectric efficiency is 3.56%.

Layer-engineered interlayer excitons

Photoluminescence (PL) from excitons serves as a powerful tool to characterize the optoelectronic property and band structure of semiconductors, especially for atomically thin two-dimensional transition metal dichalcogenide (TMD) materials. However, PL quenches quickly when the thickness of TMD materials increases from monolayer to a few layers, due to the change from direct to indirect band transition. Here, we show that PL can be recovered by engineering multilayer heterostructures, with the band transition reserved to be a direct type. We report emission from layer-engineered interlayer excitons from these multilayer heterostructures. Moreover, as desired for valleytronics devices, the lifetime, valley polarization, and valley lifetime of the generated interlayer excitons can all be substantially improved as compared with that in the monolayer-monolayer heterostructure. Our results pave the way for controlling the properties of interlayer excitons by layer engineering.

Benzotriazacycle Cored Perylene Diimide Non-fullerene Acceptors for High-performance Organic Solar Cells

Background: Perylene diimide (PDI) is among the most investigated non-fullerene electron acceptor for organic solar cells (OSCs). Constructing PDI derivatives into three-dimensional propeller-like molecular structures is not only one of the viable routes to suppress the over aggregation tendency of the PDI chromophores, but also raises possibilities to tune and optimize the optoelectronic property of the molecules. Objective: In this work, we reported the design, synthesis, and characterization of three electron-accepting materials, namely BOZ-PDI, BTZ-PDI, and BIZ-PDI, each with three PDI arms linked to benzotrioxazole, benzotrithiazole, and benzotriimidazole based center cores, respectively. Method: The introduction of electron-withdrawing center cores with heteroatoms does not significantly complicate the synthesis of the acceptor molecules but drastically influences the energy levels of the propeller-like PDI derivatives. Result: The highest power conversion efficiency was obtained with benzoxazole-based BOZ-PDI reaching 7.70% for its higher photon absorption and charge transport ability. Conclusion: This work explores the utilization of electron-withdrawing cores with heteroatoms in the propeller-like PDI derivatives, which provides a handy tool to construct high-performance non-fullerene acceptor materials.

Correction: Using high-throughput virtual screening to explore the optoelectronic property space of organic dyes; finding diketopyrrolopyrrole dyes for dye-sensitized water splitting and solar cells

Correction for ‘Using high-throughput virtual screening to explore the optoelectronic property space of organic dyes; finding diketopyrrolopyrrole dyes for dye-sensitized water splitting and solar cells’ by Isabelle Heath-Apostolopoulos et al., Sustainable Energy Fuels, 2021, DOI: 10.1039/d0se00985g.

Mutually exclusive hole and electron transfer coupling in cross stacked acenes

Topology of frontier molecular orbitals (FMOs) induce highly sensitive charge transfer coupling with variation in intermolecular arrangement. A consistent optoelectronic property correlated to a specific aggregate architecture independent of the...

Optoelectronic Property Comparison for Isostructural Cu2BaGeSe4 and Cu2BaSnS4 Solar Absorbers

To target mitigation of anti-site defect formation in Cu2ZnSnS4-xSex, a new class of chalcogenides, for which Ba or Sr (group 2) replace Zn (group 12), has recently been introduced for...