Molecularly Thin 2D Organic Single Crystals: A New Platform for High-Performance Polarization-Sensitive Phototransistors.

The inherent linear dichroism (LD), high absorption, and solution processability of organic semiconductors hold immense potential to revolutionize polarized light detection. However, the disordered molecular packing inherent to polycrystalline thin films obscures their intrinsic diattenuation, resulting in diminished polarization sensitivity. In this study, we develop filter-free organic polarization-sensitive phototransistors (PSPs) with both a high linear dichroic ratio (LDR) and exceptional photosensitivity utilizing molecularly thin dithieno[3,2-b:2',3'-d]thiophene derivatives (DTT-8) two-dimensional molecular crystals (2DMCs) as the active layer.

Broadband Green Luminescence and Phase Transition in Low-Dimensional Organic-Inorganic Hybrid Iodate.

Organic-inorganic hybrid iodide systems, which can form highly ordered chromophores and uniformly oriented transition dipole moments, serve as optimal host-guest systems for the fabrication of micrometer-scale optical devices. In particular, those with low-dimensional structures can exhibit strong quantum-limited and highly localized charges, enabling the generation of high exciton energies and stable excitation emission. In this study, we report a novel instance of an organic-inorganic hybrid iodate, (CHN)(IO), which was synthesized by incorporating the optically active organic compound, 9-aminoacridine.

Organic Single-Crystalline Microwire Arrays toward High-Performance Flexible Near-Infrared Phototransistors.

Flexible organic near-infrared (NIR) phototransistors hold promising prospects for potential applications such as noninvasive bioimaging, health monitoring, and biometric authentication. For integrated circuits of high-performance devices, organic single-crystalline micro-/nanostructures with precise positioning are prominently anticipated. However, the manufacturing of organic single-crystalline arrays remains a conundrum due to difficulties encountered in patterning arrays of dewetting processes at micron-scale confined space and modulating the dewetting dynamics.

Chiral Lead-Free Double Perovskite Single-Crystalline Microwire Arrays for Anisotropic Second-Harmonic Generation.

Halide double perovskites present a new branch for versatile optoelectronic devices because of their huge structural compatibility and environmental friendliness, whereas nonlinear optics (NLO) devices remain blank for this fascinating family. Simultaneously, the precise patterning of single-crystalline perovskite microwire arrays remains a challenge for the integration of NLO devices. Herein, we designed lead-free chiral 2D double perovskites with the nonsymmetrical structure presenting second-harmonic generation (SHG).

High-energy, tunable, long-wave mid-infrared optical parametric oscillator based on BaGaSe crystal.

A high-energy, tunable, long-wave mid-infrared optical parametric oscillator (OPO) based on the crystal was demonstrated in this Letter with 1064 nm laser pumping. The mid-infrared OPO was designed as a double-pass single resonant oscillator (DP-SRO) to reduce the threshold and improve the outputs. Further optimization on the cavity length was theoretically and experimentally studied.

SrGaOS: A Nonlinear Optical Oxysulfide with Melilite-Derived Structure and Wide Band Gap.

SrGaOS, which is a novel nonlinear optical oxysulfide, was discovered via solid-state reaction. The compound crystallizes in noncentrosymmetric space group 222 (No. 18) of the orthorhombic system.

Two rare-earth-based quaternary chalcogenides EuCdGeQ (Q = S, Se) with strong second-harmonic generation.

Two new rare-earth-based chalcogenides EuCdGeQ4 (Q = S, Se) have been designed and constructed by using Eu2+ and the classical NLO-active SBUs of [CdQ4] and [GeQ4]. They crystallize in a non-centrosymmetric Ama2 (no. 40) space group.

AHgSnQ (A = Sr, Ba; Q = S, Se): A Series of Hg-Based Infrared Nonlinear-Optical Materials with Strong Second-Harmonic-Generation Response and Good Phase Matchability.

Four Hg-based IR nonlinear-optical materials, AHgSnQ (A = Sr, Ba; Q = S, Se), were discovered and investigated systematically. Their structures are built of two-dimensional [HgSnQ] layers, which are assembled alternately by distorted (HgQ and SnQ) tetrahedra and separated by eight-coordinated A cations. The two sulfides AHgSnS (A = Ba, Sr) exhibit large second-harmonic-generation (SHG) responses (2.

Synthesis, Structure, and Characterization of Two Mixed-Cation Quaternary Chalcogenides KBaSnQ (Q = S, Se).

Two new isostructural metal chalcogenides, KBaSnS and KBaSnSe, have been isolated for the first time. They feature the intriguing ∞ 1[BaSnQ] (Q = S, Se) tunnel structures which are separated by K cations. Experiments combined with theoretical calculations demonstrate that KBaSnS possesses a large energy gap (3.

High energy and tunable mid-infrared source based on BaGaSe crystal by single-pass difference-frequency generation.

A high-energy and tunable mid-infrared source based on BaGaSe crystal was demonstrated by single-pass difference-frequency generation (DFG). Orthogonally polarized wave at 1064 nm (λ) and tunable idler wave (λ) generated by KTP-OPO, which could be tuned in the wavelength range of 1360-1600 nm, were used as the DFG dual-wavelength pump. The pump parameters including total pump energy and energy ratio were studied.

High-conversion-efficiency tunable mid-infrared BaGaSe optical parametric oscillator pumped by a 2.79-μm laser.

A mid-infrared BaGaSe optical parametric oscillator with high conversion efficiency and beam quality is demonstrated, which is pumped by a 2.79-μm electro-optically Q-switched Cr, Er:YSGG laser. A pulse energy of 3.

SnGaGeSe, a benign addition to the AMMQ family: synthesis, crystal structure and nonlinear optical performance.

A new selenide, SnGa2GeSe6, in the AMIII2MIVQ6 family was synthesized for the first time by a high-temperature solid-state reaction. It crystallized in the non-centrosymmetric space group Fdd2 with cell dimensions of a = 47.195(9) Å, b = 7.

Sr Cd Sb O S : Strong SHG Response Activated by Highly Polarizable Sb/O/S Groups.

A new nonlinear optical (NLO) oxysulfide, Sr Cd Sb O S , which contains the functional groups [SbO S ] (x=0, 1) with a 5s electron configuration, is synthesized by a solid-state reaction. This compound displays a phase-matchable second harmonic generation (SHG) response four times stronger than AgGaS (AGS) under laser irradiation at 2.09 μm.

Continuous-wave difference-frequency generation based on BaGaSe crystal.

A continuous-wave mid-infrared radiation from difference frequency generation by mixing a continuous-wave Ti: sapphire laser and a continuous-wave YAG laser in a 15 mm long BaGaSe crystal is demonstrated for the first time. The tunable range from 3.15 to 7.

ZnPS: A Promising Infrared Nonlinear-Optical Material with Excellent Overall Properties.

The thiophosphate ZnPS is reported for its potential application in infrared (IR) nonlinear optics. This nondeliquescent compound features a cubic closet packing of the (PS) groups, with Zn filling in three-quarters of the tetrahedral interspaces. The optical band gap of ZnPS is characterized as 3.

Synthesis, Crystal Structure, and Optical Properties of Noncentrosymmetric NaZnSnS.

A new chalcogenide NaZnSnS has been successfully synthesized by using NaS as reactive flux. NaZnSnS crystallizes in the tetragonal system with space group of I4̅. Its cell parameters are a = 6.

KZnGeS: A Congruent-Melting Infrared Nonlinear-Optical Material with a Large Band Gap.

KZnGeS belonging to the noncentrosymmetric space group P2 of the monoclinic system was discovered via a solid-state method. It possesses two-dimensional [ZnGeS] layers, with alkali-metal cations K located between the layers. On the basis of UV-vis-near-IR diffuse-reflectance spectrometry, the band gap of KZnGeS is 3.

Nonbonding Electrons Driven Strong SHG Effect in HgGeSe: Experimental and Theoretical Investigations.

A Hg-based ternary infrared nonlinear optical (NLO) material, HgGeSe, with the defect diamond-like (DL) structure was systematically investigated for the first time. The experimental results show that HgGeSe exhibits an enhanced second harmonic generation (SHG) response about 2.1 times that of the normal DL selenide AgGaSe ( d = 33 pm/V) at the particle size of 150-200 μm, as well as good phase-matchable ability.

Li Cd Ge Se and Li Cd Sn Se : Strong Nonlinear Optical Response in Quaternary Diamond-Like Selenide Networks.

Two new selenides with diamond-like structures, Li Cd Ge Se and Li Cd Sn Se , were synthesized by using a conventional high-temperature solid-state reaction method. They crystallize in the space group Pna2 (no. 33) of the orthorhombic system.

PbMnGaS and PbMnGaSe: Two Quaternary Metal Chalcognides with Open-Tunnel-Framework Structures Displaying Intense Second Harmonic Generation Responses and Interesting Magnetic Properties.

By combining different nonlinear optical-active structural chromophores with transition metal Mn into a crystal structure, two novel quaternary metal chalcogenides PbMnGaS (1) and PbMnGaSe (2) were successfully synthesized. Compounds 1 and 2 are isostructural, and they represent a new structure type that crystallizes in the space group P6̅ (No. 174) in the hexagonal system.

K ZnSn Se : A Non-Centrosymmetric Zinc Selenidostannate(IV) Featuring Interesting Covalently Bonded [ZnSn Se ] Layer and Exhibiting Intriguing Second Harmonic Generation Activity.

Non-centrosymmetric zinc selenidostannate(IV) K ZnSn Se was synthesized. It features interesting covalently bonded [ZnSn Se ] layers with K cations filling in the interlayer voids. The phonon spectrum was calculated to clarify its structural stability.

BaAuS: A Au-Based Intrinsic Photocatalyst for High-Performance Visible-Light Photocatalysis.

A new Au-based sulfide BaAuS was obtained through solid-state reaction. It crystallizes in the tetragonal space group I4/amd with unit cell parameters of a = 6.389 72(2) Å, b = 6.