Chinese researchers develop perovskite solar cells with enhanced stability

A research team led by Prof. GAO Peng from Fujian Institute of Research on the Structure of Matter of the Chinese Academy of Sciences has developed high-performance perovskite solar cells with enhanced environmental stability.

The team reported a 2-(4-fluorophenyl)ethylamine (FPEA: 4-FC6H4C2H4NH3) bulky cation to grow a 2D perovskite overlayer on the top of the Cs/FA/MA triple-cation 3D perovskite to combine the high stability of 2D perovskite with high efficiency of 3D perovskite simultaneously.

2D MXenes may improve perovskite solar cell efficiency

Researchers at the University of Rome Tor Vergata in Italy and Russia’s NUST MISIS institute have investigated how cells containing two-dimensional titanium-carbide MXene support layers could improve perovskite solar cell performance.

To obtain good power conversion within a perovskite solar cell, all layers and layer interfaces within the cell must have good compatibility. Typical cells contain the active perovskite material sandwiched between two charge transport layers, which are then adjacent to their corresponding electrodes. Support layers may also be added. Charge mobility, energy barriers, interface energy alignment, and interfacial vacancies all impact compatibility and subsequent cell performance and stability. Thus, engineering well-suited interfaces with the cell is paramount to cell success and long-term stability, an important criterion for potential commercialization.

Korean team uses a transparent conductive adhesive to combine perovskite and silicon solar cells

Researchers from the Ulsan Institute of Science and Technology (UNIST) have demonstrated a new method of fabricating perovskite-on-silicon tandem devices, using a transparent conductive adhesive (TCA) to combine the two cells. The scientists have developed devices with demonstrated efficiencies of 19.4%, and propose methods to bring that up to over 24% using existing technology.

While the efficiency is still well below the 28% record for a perovskite/silicon tandem cell set by Oxford PV, the UNIST group says its method is far simpler to manufacture than previous concepts. “It is meaningful to develop an attached tandem solar cell unlike the conventional tandem solar cell with stacked structure,” said UNIST’s In Young Choi, lead author of the study. “We have observed that the TCA effectively connects the different light-absorbing layers.”

Researchers find environmental impacts on organometal halide perovskites

Researchers from the University of Tennessee and Oak Ridge National Laboratory have found that the environment is a non-trivial component in the operation of organometal halide perovskite (OMHP) devices, playing an important role in the charge transport behavior at the electrode/crystal interface of OMHPs due to coupling between surface mediated redox processes and bulk ionic species.

Environment factors impact transport and stability in OMHPs and but offer new opportunities in sensing and energy storage image

The team explored environmental and interface effects, namely transport behavior and origins of the gas sensitivity, in MAPbBr3 single crystal (SC) devices using impedance spectroscopy and G-Mode Kelvin Probe Force Microscopy (G-KPFM). Strong resistive response was found to occur when the crystals were exposed to different environments. It was shown, among other things, that SC response to the environment is extremely different at the surface as compared to the bulk due to the disorder surface chemistry.

Mixing perovskite nanoparticles with 2D perovskites may give a boost to the efficiency of blue LEDs

Researchers from Zhejiang University, the Beijing Institute of Technology and Nanjing Tech University in China, Argonne National Laboratory in the U.S, University of Cambridge in the UK have combined perovskite nanoparticles with 2D perovskites to double the efficiency of blue LEDs.

Perovskite particle mix to push forward blue LEDs imageBromide perovskite films consisting of nanoparticles embedded within 2-D perovskite layers produce blue LEDs with a record-high efficiency of 9.5%

While the device only glows for a few minutes, the work is still considered “a big step toward the development of high-performance blue perovskite emitters” says Jianjun Tian of the University of Science and Technology in Beijing, who was not involved in the work. “The efficiency of these blue perovskite LEDs is already higher than that of the commercially available blue organic LEDs.”