Quasi-two dimensional perovskites have emerged as candidates of high-performance materials for various optoelectronic applications due to the unique excitonic properties in their multilayer structures. Both Dion–Jacobson perovskites and Ruddlesden-Popper phases...

Quasi-two-dimensional (quasi-2D) Ruddlesden−Popper perovskites (RPPs) have been reported recently as laser media. The carrier dynamics of lasing in quasi-2D RPP films is still controversial. This work presents the amplified spontaneous emission (ASE) at room temperature based on the solution-processed quasi-2D (PEA) 2 Cs n−1 Pb n Br 3n+1 (⟨n⟩ = 3−5) thin films.Transient absorption spectroscopy was conducted to demonstrate the accumulation of excitons and population inversion for ASE caused by the energy transfer process along cascade quantum wells. The competition between the ASE and Auger recombination processes was observed via systematic and quantitative studies on the carrier dynamics. It is found that the contribution of Auger recombination is reduced by decreasing the temperature or adjusting the domain distribution of the quasi-2D RPP films, in order to achieve lower thresholds. This work re-emphasizes the importance of Auger recombination control for achieving low-threshold electrically or continuous-wave driven lasers and deepens the fundamental understanding of charge carrier dynamics of lasing in quasi-2D perovskite films.

Organic photovoltaic cells (OPVs) have great potential for driving the indoor electronic devices for internet of things (IoTs). Under indoor illuminations, the thick active layer can produce high photocurrent due...

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