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GaAs-based p-i-n 850 nm infrared photodetectors with a narrow bandpass characteristic were successfully fabricated and demonstrated by epitaxial growth technology. The photo to dark current ratios of the fabricated PDs were $1.76\times10$ 7 and $2.08\times10$ 3 at 0 and −5 V, respectively. It can be seen clearly that our fabricated PDs can achieve a very steeply and rapidly falling cut-off bandpass characteristic by inserting a p-Al0.1Ga0.9As filter layer. The full width at half maximum of the photo response was only 65.9 nm. Then, the peak responsivity value of the fabricated PDs occurred at 855 nm was 0.49 A/W with a quantum efficiency of 71.2% at −1 V. Moreover, the low frequency noise of the fabricated PDs was dominated by 1/f-type noise. And, the best detectivity was calculated to be $1.17\times10$ 13 cmHz0.5W−1 at a bias voltage of 0 V.

Four new donor-acceptor-acceptor' (D-A-A')-configured donors, CPNT, DCPNT, CPNBT, and DCPNBT equipped with naphtho[1,2-c:5,6-c']bis([1,2,5]-thiadiazole) (NT) or naphtho[2,3-c][1,2,5]thiadiazole (NBT) as the central acceptor (A) unit bridging triarylamine donor (D) and cyano or dicyanovinylene acceptor (A'), were synthesized and characterized. All molecules exhibit bathochromic absorption shifts as compared to those of the benzothiadiazole (BT)-based analogues owing to improved electron-withdrawing and quinoidal character of NT and NBT cores that lead to stronger intramolecular charge transfer. Favorable energy level alignments with C70 , together with the good thermal stability and the antiparallel dimeric packing render CPNT and DCPNT suitable donors for vacuum-processed organic photovoltaics (OPV)s. OPVs based on DCPNT : C70 active layers displayed the best power conversion efficiency (PCE)=8.3%, along with an open circuit voltage of 0.92 V, a short circuit current of 14.5 mA cm-2 and a fill factor of 62% under 1 sun intensity, simulated AM1.5G illumination. Importantly, continuous light-soaking with AM 1.5G illumination has verified the durability of the devices based on CPNT:C70 and DCPNT : C70 as the active blends. The devices were examined for their feasibility of indoor light harvesting under 500 lux illumination by a TLD-840 fluorescent lamp, giving PCE=12.8% and 12.6%, respectively. These results indicate that the NT-based D-A-A'-type donors CPNT and DCPNT are potential candidates for high-stability vacuum-processed OPVs suitable for indoor energy harvesting.

An acceptor-donor-acceptor (A-D-A)-type non-fullerene acceptor (NFA), PTTtID-Cl, featuring thieno[3,2-b]thieno[2''',3''':4'',5'']-pyrrolo[2'',3'':4',5']thieno[2',3':4,5]thieno-[2,3-d]pyrrole (DTPTt) as the electron-rich core and 2-(5,6-dichloro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (ID-Cl) as the peripheral electron-deficient terminal group was synthesized and characterized. PTTtID-Cl exhibited strong absorption in the range of 700-850 nm in CHCl3 and redshifted absorption centered at 881 nm in a thin film. The near infrared (NIR)-absorption of PTTtID-Cl was combined with a low-bandgap polymer donor (PTB7-Th) to achieve binary and semitransparent organic photovoltaics (OPVs) with a power conversion efficiency (PCE) of 8.9 % and 7.7 % (with an average visible transmittance (AVT) of 16.7 %), respectively. A ternary device with a ratio of PM7/PTTtID-Cl/IT-4F=1:0.15:0.85 (w/w) achieved a short-circuit current density of 19.46 mA cm-2 , an open-circuit voltage of 0.87 V, and a fill factor of 71.2 %, giving a PCE of 12.0 %. In addition, by employing the Ag/ITO/Ag microcavity structure, semitransparent colorful binary organic photovoltaics (OPVs) with superior transparency of 27.9 % at 427 nm and 22.7 % at 536 nm for blue and green devices, respectively, were prepared. The semitransparent colorful devices based on the optimized ternary blend gave PCEs of 8.7 %, 8.4 %, and 9.1 % for blue, green, and red devices, respectively. These results indicate the promising potential of PTTtID-Cl as a NIR-absorption NFA for applications in semitransparent colorful binary and ternary OPVs.

Two new asymmetric D−π−A1−A2 configured small molecules named PTP and TTP bearing thieno[3,4-b]pyrazine (TP) unit as the A1 group have been designed and synthesized for solution-processed bulk-heterojunction organic solar cells (OSCs). These new dipolar molecular donors not only exhibit strong near-IR absorption but pack into antiparallel dimers, in which PTP shows a coexistence of coplanar and cofacial antiparallel dimers configuration, while TTP reveals a coplanar centrosymmetric dimer structure. Solution-processed OSCs for PTP blended with pristine C70 achieves a promising power conversion efficiency (PCE) of 3.40% along with an open-circuit voltage (VOC) of 0.64 V, a short-circuit current density (JSC) of 9.83 mA cm−2 and a fill factor (FF) of 54.0%, which is the highest efficiency to date among the TP-based materials. Conversely, the optimized TTP:C70 solar cell delivers a VOC of 0.48 V, a JSC of 6.02 mA cm−2 and a FF of 43.3%, corresponding to a moderate PCE of 1.25%.

Dual-band metal&ndash, semiconductor&ndash, metal (MSM) photodetectors (PDs) with a Ga2O3/MgZnO heterostructure were fabricated by radio frequency (RF) sputtering, which can detect ultraviolet C (UVC) and ultraviolet B (UVB) bands individually by controlling different bias voltages. A PD with the annealing temperature of Ga2O3 at 600 &deg, C can improve the crystal quality of Ga2O3 thin film and exhibit the least persistent photoconductivity (PPC) effect. However, a PD with the annealing temperature of Ga2O3 at 600 &deg, C cannot achieve a voltage-tunable dual-band characteristic. On the contrary, the PD without annealing can suppress the carriers from the bottom layer of MgZnO thin film at a lower bias voltage of 1 V. At this time, the peak responsivity at 250 nm was mainly dominated by the top layer of Ga2O3 thin film. Then, as the bias voltage increased to 5 V, the peak detection wavelength shifted from 250 (UVC) to 320 nm (UVB). In addition, the PD with a 25 nm&ndash, thick SiO2 layer inserted between Ga2O3 and MgZnO thin film can achieve a broader operating bias voltage range for dual-band applications.

Many heteroacenes have been extensively studied to improve device performances; however, the morphological effects stemmed from the chemical modification on a multiscale remain less explored. In this research, five axisymmetric S,N-heteropentacenes (DTPT, DTPT-Ph, DTPT-CN, DTPT-PYCN, and DTPT-BTCN) are studied to reveal the influences of molecular symmetry and end-capping substituents on the structure-property relationship, the thermal stability, crystallization behavior, film morphology, and OFET performance. Phase behavior was probed by differential scanning calorimetry (DSC), while the quality of the crystal array and structural details was investigated by optical microscopy (OM) and grazing-incidence wide-angle X-ray scattering (GIWAXS). The analytic results reveal that (1) the parent axisymmetric S,N-heteropentacene, DTPT, is hard to crystallize, which hinders the preparation of high-quality crystal arrays for the OFET application. (2) The incorporation of π-conjugated electron-withdrawing (π-EW) endcaps that provide extended conjugation length and enhanced molecular polarity is required to form oriented crystal arrays to deliver reasonable OFET characteristics. (3) The π-EW endcaps with conformational freedom, such as -BTCN, due to the asymmetric feature of benzothiadiazole (BT), can hinder bulk phase crystallization and cause conformational disorder in the crystal array. Hence, the tradeoff of introducing the end-substituents to reinforce the poor crystalline nature of S,N-heteroacenes should be carefully considered.

In this study, we synthesized 5,11-dihexyl-4,4,10,10-tetraoctylbenzo[1,2- b:4,5- b']bisthieno[4″,5″- b″:4‴,5‴- b‴]silolo[2″,3″- d:2‴,3‴- d']thiophene (ArSi) as a ladder-type electron-rich core for the preparation of three acceptor-donor-acceptor-type nonfullerene acceptors (NFAs)-ArSiID, ArSiID-F, and ArSiID-Cl-featuring (3-oxo-2,3-dihydro-1 H-inden-1-ylidene)malononitrile (ID), 2-(5,6-difluoro-3-oxo-2,3-dihydro-1 H-inden-1-ylidene)malononitrile (ID-F), and 2-(5,6-dichloro-3-oxo-2,3-dihydro-1 H-inden-1-ylidene)malononitrile (ID-Cl) as peripheral electron-poor units, respectively. These molecules exhibit strong absorption covering the region of 600-850 nm. The incorporation of the halogen atoms onto the terminal units adjusted the energy levels and light-harvesting ability of these materials. We employed the conjugated polymers J51 and PBDB-T, having middle optical energy gaps as donor together with these ArSi derivatives as acceptor to study the blend film morphology and the corresponding organic photovoltaic (OPV) performances. After optimization with device engineering works, a PBDB-T:ArSiID-F-based device with a power conversion efficiency up to 9.4% was achieved. This study is the first case to examine the effects of various halogen modifications on the performance of ArSi derivatives that serve as NFAs for OPVs. Our findings should encourage further investigations on this rarely studied core structure for optoelectronic applications.

Ternary blend organic photovoltaics (OPVs) have been introduced to improve solar spectral absorption and reduce energy losses beyond that of binary blend OPVs, but the difficulties in simultaneously optimizing the morphology of three molecular components result in devices that have generally exhibited performance inferior to that of analogous binary OPVs. Here, we introduce a small molecule-based biternary OPV comprising two individual, vacuum-deposited binary bulk heterojunctions fused at a planar junction without component intermixing. In contrast to previous reports where the open circuit voltage (

Three D-A-D-configured molecules DTPBT, DTPNT, and DTPNBT with high quantum yield of orange red (628 nm), red (659 nm), and deep-red/NIR (710 nm) fluorescence, respectively, were developed as emitting dopants in an exciplex-forming cohost (TCTA:3P-T2T) for high-efficiency fluorescence-based organic light-emitting diodes (OLEDs). The obtained physical properties together with theoretical calculations analyzed from these new molecules establish a clear structure-property relationship, in which the feature of central acceptor 2,1,3-benzothiadiazole (BT), naphtho[1,2-c:5,6-c']bis[1,2,5]thiadiazole (NT), and 2,1,3-naphthothiadiazole (NBT) plays the crucial role for governing the physical characteristics. The optimized device configured as ITO/HAT-CN/TAPC/TCTA/TCTA:3P-T2T:5% emitter/3P-T2T/LiF/Al gave a record-high efficiency of orange red (591 nm, 15%), red (647 nm, 10%), and deep-red/NIR (689 nm, 9%) electroluminescent devices. The effective harvest of triplet excitons with an exciplex-forming system in conjunction with efficient energy transfer between the exciplex and the dopant is beneficial for such high device efficiencies. More importantly, the stable exciplex-forming cohost and fast radiative decay rate of DTPNT render this particular device exhibiting high device stability as indicated by the low efficiency roll-off under high current densities (EQE (external quantum efficiency) values of 8.1% at 1000 cd m-2 and 6.8% at 10,000 cd m-2). These results reveal the potential of employing an exciplex-forming system as cohost for fluorescent dopants to furnish high-efficiency OLEDs with an emission wavelength extending to the red or even the NIR range.

Although chemical modifications on conjugated molecules are widely applied for the purpose of improving processability and device performances, the effect of the modification was far less investigated. Here, five S, N-hexacenes are studied to reveal the influences of (1) the lateral alkyl chain, (2) the terminal group (thiophene vs benzene), and (3) the end-capping phenyl group of the hexacenes on the morphology and organic field-effect transistor (OFET) performances. Crystal arrays of the hexacenes were prepared via polydimethylsiloxane (PDMS)-assisted crystallization (PAC) prior to morphological and OFET characterizations. The lattice structures and crystal quality of the hexacenes were evaluated by microscopy and diffraction techniques including single-crystal diffractometer, electron diffraction, and grazing incidence wide-angle X-ray scattering. The systematic analyses led to the following conclusions: (1) the bulkier alkyl side chain assists to form more densely packed crystals with less structural defects; (2) the terminal thiophene rings bring about higher-lying E

In this study, we demonstrate a novel micro-cavity forming electrode with a sandwiched structure of Ag/HATCN/Ag. This new electrode presents high transmittance in visible wavelengths and reveals the capability of modulating the wavelength of transmitted light by precisely adjusting the thickness of HATCN interlayer. Notably, the Ag/HATCN/Ag electrode possesses excellent thermal stability that leads to an insignificant peak shift of the transmittance spectrum after thermal aging as exposed to air. This new electrode can be applied to both the solution-processed polymer solar cell (PSC) and thermally evaporated small molecule solar cell (SMSC). The implementation of the Ag/HATCN/Ag electrode for the blue, green, and red PSCs with PM6:Y6 as the photoactive blend results in the power conversion efficiency (PCE) over 13%, representing the highest performance for colorful PSCs ever reported. Significantly, the blue PSC shows the highest PCE up to 13.54% with a maximum transmittance of 15.6%. In addition, vacuum-processed red SMSC based on the active layer composed of DTDCPB:C70 blend shows a PCE and a maximum transmittance of 7.84% and 26.4%, respectively, while the blue and green SMSCs also exhibit PCE higher than 7%. The high PCE and the good transmittance of both the PSC and SMSC imply that the new micro-cavity forming Ag/HATCN/Ag electrode has promising potential in various practical applications.

Objective: Incarcerated gravid uterus is a rare complication of pregnancy and can become a critical condition during delivery. For extremely uncommon cases that persist to the third trimester, correct diagnosis before delivery and appropriate management of the associated complications are important. Case report: This was the first case of a full-term pregnancy with incarcerated gravid uterus, reported at a medical center. The condition was not diagnosed during pregnancy, which led to serious complications during the cesarean delivery; however, the prognosis was favorable because of the timely management. Conclusion: Based on the previous case reports and clinical presentation of this case, early diagnosis with ultrasound and pelvic examination is the key to successful treatment. Vertical and more cephalad uterine incision reduces the risk of bladder perforation and injury to the cervix and vagina. A successful teamwork of obstetricians, gynecologists, urologists, and anesthesiologists can ensure favorable outcomes for both mother and fetus. Keywords: Cesarean delivery, Incarcerated gravid uterus, Third trimester

The use of multiple donors in an active layer is an effective way to boost the efficiency of organic solar cells by broadening their absorption window. Here, we report an efficient vacuum-deposited ternary organic photovoltaic (OPV) using two donors, 2-((2-(5-(4-(diphenylamino)phenyl)thieno[3,2-b]thiophen-2-yl)thiazol-5-yl)methylene)malononitrile (DTTz) for visible absorption and 2-((7-(5-(dip-tolylamino)thiophen-2-yl)benzo[c]-[1,2,5]thiadiazol-4-yl)methylene)malononitrile (DTDCTB) for near-infrared absorption, codeposited with C70 in the ternary layer. The ternary device achieved a power conversion efficiency of 8.02%, which is 23% higher than that of binary OPVs. This enhancement is the result of incorporating two donors with complementary absorption covering wavelengths of 350 to 900 nm with higher hole mobility in the ternary layer than that of binary layers consisting of one donor and C70, combined with energy transfer from the donor with lower hole mobility (DTTz) to that with higher mobility (DTDCTB). This structure fulfills all the requirements for efficient ternary OPVs.

GaN metal-semiconductor–metal (MSM) ultraviolet photodetectors (PDs) with ex situ sputtered AlN nucleation layer were investigated and demonstrated. The crystal quality, electrical, and optical properties of GaN PDs were improved using ex situ sputtered AlN nucleation layer. Compared with in situ AlN nucleation layer, it was found that the X-ray rock curve widths and yellow or blue bands of cathodoluminescence spectra of the PDs prepared by ex situ sputtered AlN nucleation layer were significantly reduced and smaller due to the improved crystal quality. It was also found that the dark current and responsivity of PDs with ex situ sputtered AlN nucleation layer were more effectively reduced and enhanced. Moreover, GaN MSM PDs with ex situ sputtered AlN nucleation layer could achieve the higher quantum efficiency and detectivity.

The finite-difference time-domain method was used to calculate the electric fields emitted from cellular phones inside an ambulance and from a transmitter on the ambulance roof. Measurements on the electric fields emitted from cellular phones inside the ambulance were also performed using a Narda Model SRM-3000 high frequency selective radiation meter. From measurement and simulation results, it is found that electric field strengths emitted from cellular phones inside the ambulance may be over the recommended electromagnetic interference immunity level of 3 V/m set by the International Electrotechnical Commission for medical devices. An interference threshold separation distance of 30 cm is proposed for evaluating the interaction between cellular phones and medical devices inside an ambulance. Simulation results of interior electric fields emitted from a transmitter on an ambulance roof made of metallic material are found not to exceed the 3 V/m standard immunity level. However, electric field strengths ...

Packing and placement are two crucial stages for FPGA realization. In the design flow, the basic logic units, such as look-up-tables (LUTs) and flip-flops (FFs), have to be merged into configurable logic blocks (CLBs) before placement. How the basic logic blocks are clustered in the packing stage has a great impact on the placement quality. This work presents an analytical placement framework for heterogeneous FPGAs through a rough-placed packing algorithm. In the packing stage, we first perform a fast wirelength-driven placement for the basic logic units. With the physical information from the initial placement, we implement an affinity-based clustering algorithm while taking the control signal constraints into consideration. In the placement stage, a quadratic global placer is implemented with the techniques of handling the heterogeneity, routing congestion estimation and cell inflation. An incremental placer is performed after the global placement for closing the gap between the global placement and legalization, and a detailed placer is adopted to legalize the blocks and reduce the wirelength. Experimental results show that the proposed methodologies can effectively improve the placement solutions.