Highly-Polarized Solar-Blind Ultraviolet Organic Photodetectors.

Developing high-performance polarization-sensitive ultraviolet photodetectors is crucial for their application in military remote sensing, detection, bio-inspired navigation, and machine vision. However, the significant absorption in the visible light range severely limits the application of polarization-sensitive ultraviolet photodetectors, such as high-quality anti-interference imaging. Here, based on a wide-bandgap organic semiconductor single crystal (trans-1,2-bis(5-phenyldithieno[2,3-b:3',2'-d]thiophen-2-yl)ethene, BPTTE), high-performance polarization-sensitive solar-blind ultraviolet photodetectors with a dichroic ratio close to 4.

High-Efficiency Area-Emissive White Organic Light-Emitting Transistor for Full-Color Display.

The construction of high-performance white organic light-emitting transistor (OLET) with uniform area emission is crucial for smart display technologies but remains greatly challenging. Herein, high-efficiency uniform area-emissive OLETs based on a unique lateral-integrated device configuration which incorporates efficient energy transfer of phosphorescent and fluorescent guests, enabling color-tunable and white emission, are demonstrated. Through precisely regulating the energy transfer between host and guests, high external quantum efficiency of 13.

Phase-pure 2D tin halide perovskite thin flakes for stable lasing.

Ruddlesden-Popper tin halide perovskites are a class of two-dimensional (2D) semiconductors with exceptional optoelectronic properties, high carrier mobility, and low toxicity. However, the synthesis of phase-pure 2D tin perovskites is still challenging, and the fundamental understanding of their optoelectronic properties is deficient compared to their lead counterparts. Here, we report the synthesis of a series of 2D tin perovskite bulk crystals with high phase purity via a mixed-solvent strategy.

Organic Polarized Light-Emitting Transistors.

Electrically driven polarized light-emitting sources are central to various applications including quantum computers, optical communication, and 3D displays, but serious challenges remain due to the inevitable incorporation of complex optical elements in conventional devices. Here, organic polarized light-emitting transistors (OPLETs), a kind of novel device that integrates the functions of organic field-effect transistors, organic light-emitting diodes, and polarizers into one unique device, are demonstrated with a degree of polarization (DOP) as high as 0.97, which is comparable to completely linearly polarized light (DOP = 1).

Harvesting Triplet Excitons in High Mobility Emissive Organic Semiconductor for Efficiency Enhancement of Light-Emitting Transistors.

Organic light-emitting transistors (OLETs), a kind of highly integrated and minimized optoelectronic device, demonstrate great potential applications in various fields. The construction of high-performance OLETs requires the integration of high charge carrier mobility, strong emission, and high triplet exciton utilization efficiency in the active layer. However, it remains a significant long-term challenge, especially for single component active layer OLETs.

Molecular doped, color-tunable, high-mobility, emissive, organic semiconductors for light-emitting transistors.

Developing high-mobility emissive organic semiconductors with tunable colors is crucial for organic light-emitting transistors (OLETs), a pivotal component of integrated optoelectronic devices, but remains a great challenge. Here, we demonstrate a series of color-tunable, high-mobility, emissive, organic semiconductors via molecular doping with a high-mobility organic semiconductor, 2,6-diphenylanthracene, as the host. The well-matched molecular structures and sizes with efficient energy transfer between the host and guest enable the intrinsically high charge transport with tunable colors.

Redistributed Current Density in Lateral Organic Light-Emitting Transistors Enabling Uniform Area Emission with Good Stability and Arbitrary Tunability.

Organic light-emitting transistors (OLETs), integrating the functions of an organic field-effect transistor (OFET) and organic light-emitting diode (OLED) in a single device, are promising for the next-generation display technology. However, the great challenge of achieving uniform area emission in OLETs with good stability and arbitrary tunability hinders their development in this field. Herein, an effective solution to obtain well-defined area emission in lateral OLETs by incorporating a charge-transport buffer (CTB) layer between the conducting channel and emitting layer is proposed.

Intrinsic Linear Dichroism of Organic Single Crystals toward High-Performance Polarization-Sensitive Photodetectors.

The ability to detect light in photodetectors is central to practical optoelectronic applications, which has been demonstrated in inorganic semiconductor devices. However, so far, the study of polarization-sensitive organic photodetectors, which have unique applications in flexible and wearable electronics, has not received much attention. Herein, the construction of polarization-sensitive photodetectors based on the single crystals of a superior optoelectronic organic semiconductor, 2,6-diphenyl anthracene (DPA), is demonstrated.

High Mobility Organic Lasing Semiconductor with Crystallization-Enhanced Emission for Light-Emitting Transistors.

The development of high mobility organic laser semiconductors with strong emission is of great scientific and technical importance, but challenging. Herein, we present a high mobility organic laser semiconductor, 2,7-diphenyl-9H-fluorene (LD-1) showing unique crystallization-enhanced emission guided by elaborately modulating its crystal growth process. The obtained one-dimensional nanowires of LD-1 show outstanding integrated properties including: high absolute photoluminescence quantum yield (PLQY) approaching 80 %, high charge carrier mobility of 0.

Organic Light-Emitting Transistors Entering a New Development Stage.

Organic light-emitting transistors (OLETs) are possibly the smallest integrated optoelectronic devices that combine the switching and amplification mechanisms of organic field-effect transistors (OFETs) and the electroluminescent characteristic of organic light-emitting diodes (OLEDs). Such a unique architecture of OLETs makes them ideal for developing the next-generation display technology and electrically pumped lasers for miniaturized photonic devices and circuits. However, the development of OLETs has been slow.

High-performance amorphous organic semiconductor-based vertical field-effect transistors and light-emitting transistors.

Herein, two kinds of vertical organic optoelectronic devices, vertical organic field-effect transistors (VOFETs) and light-emitting transistors (VOLETs), were constructed based on amorphous organic semiconductors of N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) as hole injecting and transport layers and tris(8-hydroxy-quinolinato) aluminum (Alq3) as the emitting layer. High device performances with a large on/off ratio of ∼6 × 103, current density of ∼40 mA cm-2, and fast response of ∼5 ms at a frequency of 20 Hz and a brightness of 126 cd m-2 were demonstrated for these two vertical devices with good device stability and repeatability. These results suggest the potential applications of amorphous organic semiconductors with good film-forming characteristics and easy device fabrication ability in vertical optoelectronic circuits.

High-Efficiency Single-Component Organic Light-Emitting Transistors.

Construction of high-performance organic light-emitting transistors (OLETs) remains challenging due to the limited desired organic semiconductor materials. Here, two superior high mobility emissive organic semiconductors, 2,6-diphenylanthracene (DPA) and 2,6-di(2-naphthyl) anthracene (dNaAnt), are introduced into the construction of OLETs. By optimizing the device geometry for balanced ambipolar efficient charge transport and using high-quality DPA and dNaAnt single crystals as active layers, high-efficiency single-component OLETs are successfully fabricated, with the demonstration of strong and spatially controlled light emission within both p- and n- conducting channels and output of high external quantum efficiency (EQE).