The fabrication and full characterization of luminescent solar concentrators (LSCs) comprising CdSe core/multishell quantum dots (QDs) is reported. TEM analysis shows that the QDs are well dispersed in the acrylic medium while maintaining a high quantum yield of 45%, resulting in highly transparent and luminescent polymer plates. A detailed optical analysis of the QD-LSCs including absorption, emission, and time-resolved fluorescence measurements is presented. Both silicon and GaAs solar cells attached to the side of the QD-LSCs are used to measure the external quantum efficiency and power conversion efficiency (2.8%) of the devices. Stability tests show only a minor decrease of 4% in photocurrent upon an equivalent of three months outdoor illumination. The optical data are used as input for a ray-trace model that is shown to describe the properties of the QD-LSCs well. The model was then used to extrapolate the properties of the small test devices to predict the power conversion efficiency of a 50×50 cm2 module with a variety of different solar cells. The work described here gives a detailed insight into the promise of QD-based LSCs

The conversion of CO2 into fuels and feedstock chemicals via photothermal catalysis holds promise for efficient solar energy utilization to tackle the global energy shortage and climate change. Despite recent advances, it is of emerging interest to explore promising materials with excellent photothermal properties to boost the performance of photothermal CO2 catalysis. Here, we report the discovery of MXene materials as superior photothermal supports for metal nanoparticles. As a proof-of-concept study, we demonstrate that Nb2C and Ti3C2, two typical MXene materials, can enhance the photothermal effect and thus boost the photothermal catalytic activity of Ni nanoparticles. A record CO2 conversion rate of 8.50 mol·gNi –1·h–1 is achieved for Nb2C-nanosheet-supported Ni nanoparticles under intense illumination. Our study bridges the gap between photothermal MXene materials and photothermal CO2 catalysis toward more efficient solar-to-chemical energy conversions and stimulates the interest in MXene-supported metal nanoparticles for other heterogeneous catalytic reactions, particularly driven by sunlight.

to millimeter scale, which is much larger than the carrier diffuse length in PSCs and thus greatly hinders their device applications. To solve this problem, a space-confined strategy was introduced into these methods to grow PSCs with thickness from several hundreds of nanometers to a few micrometers. [14,17−19] However, the lateral dimension of the resulting PSCs was limited by lack of solution supplement at the confined areas to provide enough solutes for continuous crystal growth. Moreover, the reported growth techniques for PSCs are quite time consuming and batch processes with limited throughput.Among various solution-based methods, blade coating has the advantages of high throughput, roll-to-roll compatibility, and minimal material wastage. [20−22] Although it has been widely applied to fabricate perovskite thin films for device applications, [23−26] PSCs deposited by the blade coating method generally exhibit a nonuniform morphology with low crystallinity, making them very challenging to fabricate high-performance integrated devices. The solution fluidic flow instabilities are believed to be the primary cause. [25,27] During the coating process, perovskite solutes would be turbulently transported to various locations of meniscus front, and this yields perovskite supersaturated phase containing randomly aggregated solutes, resulting in inhomogeneous nucleation and formation of the nonuniform and misaligned seed crystals. Therefore, it still remains a great challenge to achieve large-area growth of PSCs with highly uniform morphology via blade coating.Herein, we report the development, for the first time, of a microchannel-confined crystallization (MCC) strategy for the large-area growth of highly aligned PSCs with uniform morphology, which is applicable to device integration. The microchannels not only helped stabilize the transport of perovskite solutes but also reduced the density of nucleation events, ensuring the formation of uniform and continuous PSCs arrays in the channels. Both in situ experimental observation and theoretical simulation verified the vital roles of the microchannel in controlling the solution flow dynamics. The resulting PSCs possess a long carrier lifetime of 175 ns and an ultralow defect density of 2 × 10 9 cm −3 , which are comparable to the corresponding Perovskite single crystals (PSCs) possess superior optoelectronic properties compared to their corresponding polycrystalline films, but their applications of PSCs in high-performance, integrated devices are hindered by their heavy thickness and difficulty in scalable deposition. Here, a microchannel-confined crystallization (MCC) strategy to grow uniform and large-area PSC arrays for integrated device applications is reported. Benefiting from the confinement effect of the microchannels, solution flow dynamics is well controlled, and thus uniform deposition of PSC arrays with suitable thickness is achieved, meaning they are applicable for scale-up device applications. The resulting PSCs possess excellent optoelectronic proper...

Photosynaptic organic field‐effect transistors (OFETs) represent a viable pathway to develop bionic optoelectronics. However, the high operating voltage and current of traditional photosynaptic OFETs lead to huge energy consumption greater than that of the real biological synapses, hindering their further development in new‐generation visual prosthetics and artificial perception systems. Here, a fully solution‐printed photosynaptic OFET (FSP‐OFET) with substantial energy consumption reduction is reported, where a source Schottky barrier is introduced to regulate charge‐carrier injection, and which operates with a fundamentally different mechanism from traditional devices. The FSP‐OFET not only significantly lowers the working voltage and current but also provides extraordinary neuromorphic light‐perception capabilities. Consequently, the FSP‐OFET successfully emulates visual nervous responses to external light stimuli with ultralow energy consumption of 0.07–34 fJ per spike in short‐term plasticity and 0.41–19.87 fJ per spike in long‐term plasticity, both approaching the energy efficiency of biological synapses (1–100 fJ). Moreover, an artificial optic‐neural network made from an 8 × 8 FSP‐OFET array on a flexible substrate shows excellent image recognition and reinforcement abilities at a low energy cost. The designed FSP‐OFET offers an opportunity to realize photonic neuromorphic functionality with extremely low energy consumption dissipation.

No abstract

A single phase CuSbSe2 polycrystalline chalcostibite compound has been facilely synthesized through mechanical alloying for the first time, and the phase evolution has been revealed in detail.

Silicon‐based electronic devices, especially graphene/Si photodetectors (Gr/Si PDs), have triggered tremendous attention due to their simple structure and flexible integration of the Schottky junction. However, due to the relatively poor light–matter interaction and mobility of silicon, these Gr/Si PDs typically suffer an inevitable compromise between photoresponsivity and response speed. Herein, a novel strategy for coupling 2D In2S3 with Gr/Si PDs is demonstrated. The introduction of the double‐heterojunction design not only strengthens the light absorption of graphene/Si but also combines the advantages of the photogating effect and photovoltaic effect, which suppresses the dark current, accelerates the separation of photogenerated carriers, and brings photoconductive gain. As a result, In2S3/graphene/Si devices present an ultrahigh photoresponsivity of 4.53 × 104 A W−1 and fast response speed less than 40 µs, simultaneously. These parameters are an order of magnitude higher than pristine Gr/Si PDs and among the best values compared with reported 2D materials/Si heterojunction PDs. Furthermore, the In2S3/graphene/Si PD expresses outstanding long‐term stability, with negligible performance degradation even after 1 month in air or 1000 cycles of operation. These findings highlight a simple and novel strategy for constructing high‐sensitivity and ultrafast Gr/Si PDs for further optoelectronic applications.

An effective approach to enhance the thermoelectric performance (ZT) of polycrystalline In4Se3 based samples by crystallographic and microstructural engineering is proposed and demonstrated. Cu intercalation, Br substitution at selenium sites, and incorporation of dispersed hierarchical nanoparticles are discussed. An improved ZT of 1.1 at 723 K is achieved in CuBr2 doped In4Se2.5.