Perovskite quantum emitters The development of many optical technologies is dependent on the availability solid-state single with near-perfect coherence. Light-emitting defects in diamond and dots grown by molecular beam epitaxy have demonstrated transform-limited emission linewidths. However, they are limited terms production scalability reproducibility between individual emitters. Utzat et al. now show that perovskite can overcome these limitations provide unprecedented versatility for...

Lead chalcogenide colloidal nanocrystals (NCs) are promising materials for solution processable optoelectronics. However, there is little agreement on the identity and character of PbS NC emission different degrees quantum confinement—a critical parameter realizing applications these nanocrystals. In this work, we combine ensemble single spectroscopies to interrogate preparations lead sulfide NCs. We use photon correlation Fourier spectroscopy (S-PCFS) measure average linewidth...

InP quantum dots (QDs) are the material of choice for QD display applications and have been used as active layers in light-emitting diodes (QDLEDs) with high efficiency color purity. Optimizing purity QDs requires understanding mechanisms spectral broadening. While ensemble-level broadening can be minimized by synthetic tuning to yield monodisperse sizes, single line widths broadened exciton-phonon scattering fine-structure splitting. Here, using photon-correlation Fourier spectroscopy, we...

Electron spin is a key consideration for the function of organic semiconductors in light-emitting diodes and solar cells, as well spintronic applications relying on magnetoresistance. A mechanism triplet excited state generation such systems by recombination electron-hole pairs. However, exact charge mechanism, whether geminate or nongeminate it involves spin-state mixing not understood. In this work, dynamics free separation competing with to polymer states studied two closely related...

Cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals (PNCs) have recently become a promising material for optoelectronic applications due to their high emission quantum yields and facile band gap tunability via both composition size. The spectroscopy of single PNCs enhances our understanding the effect confinement on excitations in absence obfuscating ensemble averaging can also inform synthetic efforts. However, PNC studies been hampered by poor photostability under confocal...

Quantum emitters capable of producing single photons on-demand with high color purity are the building blocks emerging schemes in secure quantum communications, computing, and metrology. Such solid-state systems, however, usually prone to effects spectral diffusion (SD), i.e., fast modulation emission wavelength due presence localized, fluctuating electric fields. Two-dimensional materials especially vulnerable SD by virtue proximity outside environment. In this study we report measurements...

Lead halide perovskite nanocrystals (LHP NCs) are an emerging materials system with broad potential applications, including as emitters of quantum light. We apply design principles aimed at the structural optimization surface ligand species for CsPbBr3 NCs, leading us to study LHP NCs dicationic quaternary ammonium bromide ligands. Through selection linking groups and aliphatic backbones guided by experiments computational support, we demonstrate consistently narrow photoluminescence line...

We report the synthesis of a novel polythiophene-based host-guest copolymer incorporating Pt-porphyrin complex (TTP-Pt) into backbone for efficient singlet to triplet polymer exciton sensitization. elucidated dynamics in thin films material by means Transient Absorption Spectrosopcy (TAS) on multiple time scales and investigated mechanism formation. During sensitization, diffusion is followed transfer from where it undergoes intersystem crossing state complex. directly monitored back found...

Multiexcitons in emerging semiconducting nanomaterials play a critical role potential optoelectronic and quantum computational devices. We describe photon resolved single molecule methods to directly probe the dynamics of biexcitons triexcitons colloidal CdSe dots. confirm that emit from spin-correlated state, consistent with statistical scaling. Contrary current understanding, we find triexciton emission is dominated by band-edge 1Se1S3/2 recombination rather than higher energy 1Pe1P3/2...

Singlet exciton fission is a mechanism that could potentially enable solar cells to surpass the Shockley-Queisser efficiency limit by converting single high-energy photons into two lower-energy triplet excitons with minimal thermalization loss. The ability make use of singlet enhance cell efficiencies has been limited, however, sparsity materials energies above bandgaps common semiconductors such as Si and GaAs. Here, we employ high-throughput virtual screening procedure discover new organic...

Single-molecule photoluminescence (PL) spectroscopy of semiconductor nanocrystals (NCs) reveals the nature exciton-phonon interactions in NCs. Understanding narrow line shapes at low temperatures and significant broadening as temperature increases remains an open problem. Here, we develop atomistic model to describe PL spectrum NCs, accounting for excitonic effects, phonon dispersion relations, couplings. We use single-molecule measurements on CdSe/CdS core-shell NCs from T=4 T=290K validate...

The inherent non-linearity of intensity correlation functions can be used to spatially distinguish identical emitters beyond the diffraction limit, as achieved, for example, in super-resolution optical fluctuation imaging (SOFI). Here, we propose a complementary concept based on spectral functions, termed (SFSR) imaging. Through theoretical and computational analysis, show that resolving time-frequency image plane improve resolution by factor 2 most cases up twofold strictly two emitters....

Abstract Copper‐based ternary (I–III–VI) chalcogenide nanocrystals (NCs) are compositionally‐flexible semiconductors that do not contain lead (Pb) or cadmium (Cd). Cu‐In‐S NCs the dominantly studied member of this important materials class and have been reported to optically‐active defect states. However, there minimal reports In‐free compositions exhibit efficient photoluminescence (PL). Here, we report a novel solution‐phase synthesis ≈4 nm defective (DNCs) composed copper, aluminum, zinc,...

As luminescence applications of colloidal semiconductor nanocrystals push toward higher excitation flux conditions, there is an increased need to both understand and potentially control emission from multiexciton states. We develop a spectrally resolved correlation method study the triply excited state that enables direct measurements recombination pathway for triexciton, rather than relying on indirect extraction rates. demonstrate that, core–shell CdSe–CdS nanocrystals, triexciton arises...

Cesium lead halide perovskite nanocrystals (PNCs) have emerged as a potential next-generation single quantum emitter (QE) material for optics and information science. Optical dephasing processes at cryogenic temperatures are critical to the quality of QE, making mechanistic understanding coherence losses fundamental interest. We use photon-correlation Fourier spectroscopy (PCFS) obtain lower bound optical times PNCs function temperature. find that 20 nm CsPbBr3 emit nearly exclusively into...

A key challenge in achieving control over photocurrent generation by bulk-heterojunction organic solar cells is understanding how the morphology of active layer impacts charge separation and particular dynamics within molecularly intermixed donor–acceptor domains versus between phase-segregated domains. This paper addresses this issue studying blends devices amorphous silicon–indacenodithiophene polymer SiIDT-DTBT acceptor PC70BM. By changing blend composition, we modulate size density pure...

Diketopyrrolopyrrole (DPP)-based polymers have been consistently used for the fabrication of solar cell devices and transistors due to existence intermolecular short contacts, resulting in high electron hole mobilities. However, they also often show limited external quantum efficiencies (EQEs). In this contribution, authors analyze limitations on EQE by a combined study exciton dissociation efficiency, charge separation, recombination kinetics thin films DPP-based donor polymer, DPPTT-T...

Abstract Copper‐based ternary (I–III–VI) chalcogenide nanocrystals (NCs) are compositionally‐flexible semiconductors that do not contain lead (Pb) or cadmium (Cd). Cu‐In‐S NCs the dominantly studied member of this important materials class and have been reported to optically‐active defect states. However, there minimal reports In‐free compositions exhibit efficient photoluminescence (PL). Here, we report a novel solution‐phase synthesis ≈4 nm defective (DNCs) composed copper, aluminum, zinc,...

Diamond color centers have proven to be versatile quantum emitters and exquisite sensors of stress, temperature, electric magnetic fields, biochemical processes. Among centers, the silicon-vacancy (SiV[Formula: see text]) defect exhibits high brightness, minimal phonon coupling, narrow optical linewidths, degrees photon indistinguishability. Yet creation reliable scalable SiV[Formula: text]-based has been hampered by heterogeneous emission, theorized originate from surface imperfections,...