Self-assembled InAs bi-quantum-dot molecules (BQDMs) on GaAs (0 0 1) have been achieved using gas-source molecular beam epitaxy (GSMBE) and characterized by atomic force microscopy (AFM) and photoluminescence (PL) measurements. After the initial InAs quantum dots are partially capped with GaAs and followed by deposition of InAs, BQDMs are formed. Photoluminescence spectra of BQDMs can be descri...

Nanocrystal quantum dots are attractive materials for applications as nanoscale light sources. One impediment to these applications is fluctuations of single-dot emission intensity, known as blinking. Recent progress in colloidal synthesis has produced nonblinking nanocrystals; however, the physics underlying blinking suppression remains unclear. Here we find that ultra-thick-shell CdSe/CdS nan...

A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitt...

Lead-halide perovskites (LHPs), in the form of both colloidal nanocrystals (NCs) and thin films, have emerged over past decade as leading candidates for next-generation, efficient light-emitting diodes (LEDs) solar cells. Owing to their high photoluminescence quantum yields (PLQYs), LHPs efficiently convert injected charge carriers into light vice versa. However, despite defect-tolerance LHPs, ...

The hot carrier cooling occurs in most photoexcitation-induced phase transitions (PIPTs), but its role has often been neglected many theoretical simulations as well proposed mechanisms. Here, by including the previously ignored real-time time-dependent density functional theory (rt-TDDFT) simulations, we investigated of PIPTs. Taking IrTe2 an example, reveal that electrons from higher energy le...

The interface between the perovskite layer and charge transport (CTL) plays an important role in photoelectric conversion of solar cells (PSCs). In essence, presence defects unideal contact at perovskite/CTL induces severe nonradiative recombination, thus limiting open‐circuit voltage fill factor PSCs. Herein, a two‐birds‐with‐one‐stone strategy to overcome earlier challenges is reported, which...

InAs/GaAs quantum dots Y. D. Jang, T. J. Badcock, D. J. Mowbray, M. S. Skolnick, J. Park, D. Lee, H. Y. Liu, M. Hopkinson, R. A. Hogg, and A. D. Andreev Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom Department of Physics, Chungnam National University, Daejeon 305-764, South Korea Department of Electronic and Electrical Engineering, University of ...

Optical and structural characterizations were conducted on an InGaAsN quantum well (QW) with large energy bandgap barrier material consisting of InGaAsP (Eg 1⁄4 1:62 eV) grown by metalorganic chemical vapor deposition. A growth pause annealing technique substantially improves both the structural and the optical quality of the QW. With an optimum growth pause of 14 s, surface roughness reduces b...

Biexciton properties strongly affect the usability of a light emitter in quantum photon sources and lasers but are difficult to measure for single fluorophores at room temperature due to luminescence intermittency and bleaching at the high excitation fluences usually required. Here, we observe the biexciton (BX) to exciton (X) to ground photoluminescence cascade of single colloidal semiconducto...

Due to small, “sub-excitonic” dimensions, semiconductor nanocrystals can produce novel electronic interactions that involve charges residing in intrinsic quantized states as well as species located at nanocrystal surfaces. Strong interactions between quantum-confined carriers open, for example, a new nanocrystal-speci fic energy relaxation channel associated with Augertype electron-hole energy ...