The performance of inverted perovskite solar cells has been limited by non-radiative recombination at the perovskite surfaces. Here, authors employ phosphonic acids and piperazinium chloride for homogeneous passivation, achieving certified efficiency of 28.9% for 60 cm2 perovskite-silicon tandems.

The fine-tuning of halide perovskite materials for both performance and stability calls for innovative tools that streamline high-throughput experimentation. Here, we present two complementary systems...

EPFL is a leading university with strong emphasis on basic sciences, engineering and life sciences. Research within its Institute of Chemical Sciences and Engineering (ISIC) includes synthetic, biolog...

A high-sensitivity, broadband, transient, full-Stokes spectroscopy setup is demonstrated, which can detect quickly varying small signals from chiral emitters.

Goal of limiting warming to 1.5C looks increasingly out of reach, study finds

npj 2D Materials and Applications - Oriented 2D Ruddlesden-Popper metal halides by pulsed laser deposition

Will the double whammy of cracking down on immigrants and defunding research weaken the US as a research hub?

Mobility measurements in highly resistive methylammonium lead iodide (MAPI) are challenging due to high impedance, ion drift, and low mobility. We show that we can address the challenge using intensity-dependent photo-Hall measurements. The key is an improved photo-Hall setup, which enables reliable Hall measurements in the dark and under low-intensity illumination. By tuning the illumination over 4 orders of magnitude, we get the additional information to simultaneously extract hole mobility, electron mobility, and background doping. For the first time, we show that a MAPI single crystal, exhibiting n-type behavior in the dark, can show p-type behavior under light due to the difference in hole and electron mobility. The data partly explain the variability in mobility reported in the literature. We show that one can erroneously extract any mobility from 0 to 25 cm2/(V s) if we restrict the experiment to a small range of illumination intensities. For our MAPI (310) crystal, the measured hole and electron mobilities are 40 and 25.5 cm2/(V s), respectively.

Vapor phase deposition of formamidinium-rich perovskites is hampered by the decomposition of formamidine in the vapor phase. We use the reversibility of this reaction to establish a dynamic equilibriu...

Fast, uncontrolled crystallization with several competing pathways makes solution-processing of phase-pure quasi-two-dimensional (quasi-2D) metal halide Ruddlesden–Popper thin films challenging. Typic...

The structural and photophysical properties of the 2D layered metal halides (4F-PMA)2GeI4 and (4F-PMA)2PbI4 are reported. For the Ge composition, reduced exciton-phonon coupling is found and the abse....

The structural and photophysical properties of the 2D layered metal halides (4F-PMA)2GeI4 and (4F-PMA)2PbI4 are reported. For the Ge composition, reduced exciton-phonon coupling is found and the abse....