Hybrid Passivated Red Organic LEDs with Prolonged Operation and Storage Lifetime.

In addition to mobile and TV displays, there is a trend of organic LEDs being applied in niche markets, such as microdisplays, automobile taillights, and photobiomodulation therapy. These applications mostly do not require to be flexible in form but need to have long operation lifetimes and storage lifespans. Using traditional glass encapsulation may not be able to fulfill the rigorous product specification, and a hybrid encapsulation method by combining glass and thin-film encapsulation will be the solution. Conventional thin-film encapsulation technology generally involves organic and inorganic multilayer films that are thick and have considerable stress. As a result, when subjected to extreme heat and stress, the film easily peels off. Herein, the water vapor transmission rate (WVTR) of a 2 µm silicon nitride film prepared at 85 °C is less than 5 × 10-5 g/m2/day and its stress is optimized to be 23 MPa. Red organic LEDs are passivated with the hybrid encapsulation, and the T95 lifetime reaches nearly 10 years if the LED is continuously driven at an initial luminance of 1000 cd/m2. In addition, a storage lifespan of over 17 years is achieved.

UV-Stable and Highly Efficient Perovskite Solar Cells by Employing Wide Band gap NaTaO3 as an Electron-Transporting Layer.

Organic-inorganic halide perovskite solar cells (PSCs) still suffer from stability issues which are caused by possible erosions from moisture, ultraviolet (UV) light, heat, and so forth. An electron-transporting layer (ETL), that is, TiO2, is a key component for state-of-the-art PSCs. However, UV-caused desorption of O2- in TiO2 would accelerate the degradation of PSCs. Herein, we explored perovskite oxide, NaTaO3, for the first time as an alternative ETL in PSCs. NaTaO3 as an ETL can effectively avoid the damage from UV irradiation, inhibit the degradation of the perovskite layer, and improve the overall stability of the PSC. PSCs fabricated with NaTaO3 yielded a power conversion efficiency (PCE) of 21.07% with a retention of more than 80% of this initial PCE after 240 min UV irradiation in air while the reference device with a PCE of 20.16% can only retain about 53% of its initial PCE after the same testing condition. The developed stable perovskite oxide material of NaTaO3 provides the diversification of electron-selective contact for highly efficient and stable PSCs.

Highly Efficient Blue Phosphorescent Organic Light-Emitting Diodes Employing a Host Material with Small Bandgap.

Blue phosphorescent organic light-emitting diode (PhOLED) with a high maximum external quantum efficiency (EQE) of 26.6% was achieved using a new material, 2,8-bis(9,9-dimethylacridin-10(9H)-yl)dibenzo[b,d]furan (DBF-DMS) with a small bandgap, as the host. The device with DBF-DMS showed improved performance compared with that with 1,3-di-9-carbazolylbenzene, which is ascribed to the enhancement in carrier injection and transporting abilities and material stability of DBF-DMS. A lifetime of more than 100 h (time to 50% of the initial luminance, 1000 cd/m(2) with an EQE of 19.6%) in the other DBF-DMS-based device is obtained by further utilizing better device structure. This is a report indicating that host material with a small bandgap like DBF-DMS can be successfully utilized toward blue PhOLEDs with high performance.

Biological characteristics of renal cancer cells after CTP-mediated cancer suppressor gene NPRL2 protein treatment.

Nitrogen permease regulator like-2 (NPRL2) has been proved to be a useful suppressor gene in treating many cancers containing renal cancer based on experiments. Transgenic technology which transfect exogenous NPRL2 gene into cancer cell was used in these experiments. However, this technology has defects, such as gene mutation and loss. Cytoplasmic transduction peptide (CTP) can be used to avoid these defects because it can directly mediate proteins to penetrate cell membrane and specifically locate in cytoplasm. In this article, CTP was used to directly mediate NPRL2 protein into the renal cancer cell line 786-O, then cell proliferation was detected by the CCK-8 method, cell cycle and apoptosis were detected by flow cytometry, cell invasion and migration ability were detected by the Transwell assay. Bcl-xl, Cyt-c and caspase-3 were detected by real-time fluorescent quantitative PCR and Western blot for the analysis of the related mechanism. The result showed that CTP successfully mediated NPRL2 protein into renal cancer cells and the growth of cells was significantly inhibited. The mechanism may be NPRL2 down-regulating the expression of Bcl-xl which can up-regulate Cyt-c and further activate caspase-3, and then a cascade reaction is caused for cell apoptosis on the classic mitochondrial apoptosis pathway.

Conductive Inorganic-Organic Hybrid Distributed Bragg Reflectors.

A conductive hybrid distributed Bragg reflector (DBR) is demonstrated, consisting of inorganic and organic semiconductor films and assembled by a thermal deposition technique. A maximum reflectance of 92.2% and a wide spectral width of more than 70 nm are achieved. The hybrid DBR shows good electrical conductivity, which provides the possibility of practical applications in novel optoelectronic devices, such as electrically pumped organic vertical-cavity surface-emitting lasers.

A solution-processed bathocuproine cathode interfacial layer for high-performance bromine-iodine perovskite solar cells.

Perovskite film generally has rough surface morphology due to the voids between the grain domains. Smoothed interface contact between the perovskite layer and the top electrode is critical for planar perovskite solar cells. We reported high efficiency bromine-iodine based perovskite solar cells with a flattening cathode interface by incorporating a solution-processed bathocuproine (sBCP) interfacial layer at the cathode side. Compared with vacuum evaporated bathocuproine (eBCP), sBCP demonstrated an excellent surface modification effect at the cathode side with very smaller charge transfer resistance. Accordingly, a high fill factor exceeding 85% and a power conversion efficiency exceeding 13% in CH3NH3PbI3-xBrx based perovskite solar cells were achieved. The largely improved fill factor was attributed to the smooth film morphology and full surface coverage of perovskite films modified by the solution-processed BCP layer.

Improved hole interfacial layer for planar perovskite solar cells with efficiency exceeding 15%.

Planar structure has been proven to be efficient and convenient in fabricating low-temperature and solution-processing perovkite solar cells (PSCs). Interface control and crystal film growth of organometal halide films are regarded as the most important factors to obtain high-performance PSCs. Herein, we report a solution-processed PEDOT: PSS-GeO2 composite films by simply incorporating the GeO2 aqueous solution into the PEDOT: PSS aqueous dispersion as a hole transport layer in planar PSCs. Besides the merits of high conductivity, ambient stability and interface modification of PEDOT: PSS-GeO2 composite films, the formed island-like GeO2 particles are assumed to act as growing sites of crystal nucleus of perovskite films during annealing. By the seed-mediation of GeO2 particles, a superior CH3NH3PbI(3-x)Cl(x) crystalline film with large-scale domains and good film uniformity was obtained. The resulting PSC device with PEDOT: PSS-GeO2 composite film as HTL shows a best performance with 15.15% PCE and a fill factor (FF) of 74%. There is a remarkable improvement (∼37%) in PCE, from 9.87% to 13.54% (in average for over 120 devices), compared with the reference pristine PEDOT: PSS based device.

Lithium hydride doped intermediate connector for high-efficiency and long-term stable tandem organic light-emitting diodes.

Lithium hydride (LiH) is employed as a novel n-dopant in the intermediate connector for tandem organic light-emitting diodes (OLEDs) because of its easy coevaporation with other electron transporting materials. The tandem OLEDs with two and three electroluminescent (EL) units connected by a combination of LiH doped 8-hydroxyquinoline aluminum (Alq3) and 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN) demonstrate approximately 2-fold and 3-fold enhancement in current efficiency, respectively. In addition, no extra voltage drop across the intermediate connector is observed. Particularly, the lifetime (T75%) in the tandem OLED with two and three EL units is substantially improved by 3.8 times and 7.4 times, respectively. The doping effect of LiH into Alq3, the charge injection, and transport characteristics of LiH-doped Alq3 are further investigated by ultraviolet photoelectron spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS).

Aqueous solution-processed GeO2: an anode interfacial layer for high performance and air-stable organic solar cells.

A simple and cheap method for depositing solution-processed GeO2 (sGeO2) film is proposed utilizing the weak solubility of GeO2 in water. X-ray photoelectron spectroscopy analysis reveals that a pure GeO2 thin film can be formed by casting its aqueous solution. This method can avoid the difficulty of vacuum evaporation by its high melting point. The sGeO2 film has been used successfully as an anode interfacial layer in poly(3-hexylthiophene) (P3HT) and indene-C60 bisadduct (IC60BA)-based bulk heterojunction organic solar cells with improved power conversion efficiency and device stability compared with that using conventional poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS); the improvement of the power conversion efficiency and the device stability are estimated to be 9% and 50%, respectively. The calculations of optical intensity in a whole cell demonstrate that a thin layer of sGeO2 could function as an optical spacer in the based bulk heterojunction (BHJ) organic solar cells (OSCs) for enhancing the light harvesting in the active layer. Interfacial evaluation by impedance spectroscopy shows that the sGeO2-based cell exists less charge carrier recombination and lower contact resistance. More importantly, the sGeO2 film processing is very simple and environmentally friendly, which has potential applications in green and low-cost organic electronics in the future.

Plasmon resonance enhanced optical absorption in inverted polymer/fullerene solar cells with metal nanoparticle-doped solution-processable TiO2 layer.

This paper investigates the effects of localized surface plasmon resonance (LSPR) in an inverted polymer/fullerene solar cell by incorporating Au and/or Ag nanoparticles (NPs) into the TiO2 buffer layer. Enhanced light harvesting via plasmonic resonance of metal NPs has been observed. It results in improved short-circuit current density (Jsc) while the corresponding open-circuit voltage (Voc) is maintained. A maximum power conversion efficiency of 7.52% is obtained in the case of introducing 30% Ag NPs into the TiO2, corresponding to a 20.7% enhancement compared with the reference device without the metal NPs. The device photovoltaic characteristics, photocurrent properties, steady-state and dynamic photoluminescences of active layer on metal NP-doped TiO2, and electric field profile in metal NP-doped TiO2 layers are systematically investigated to explore how the plasmonic effects of Au and/or Ag NPs influence the OSC performance.

The synthesis and luminescence of europium (III) complex based on deprotonated 1-(4-ethyl-4H-thieno[3,2-b]indol-6-yl)-4,4,4-trifluorobutane-1,3-dionate and 1,10-phenanthroline.

A new ß-diketone ligand, 1-(4-ethyl-4H-thieno[3,2-b]indol-6-yl)-4,4,4-trifluoro-butane-1,3-dione(HL) was synthesized by four steps reaction (Suzuki-Miyaura cross-coupling, Cadogan cyclization, N-ethylation and Claisen condensation reaction) from 1-(4-bromo-3-nitrophenyl)ethanone and thiophen-2-ylboronic acid. Deprotonated ligand (L(-1)) and 1,10-phenanthroline (phen) coordinated to Eu(3+) to obtain a new europium (III) complex, EuL(3)(phen). The complex was characterized by elementary analysis, IR, (1)H NMR, UV-Visible absorption spectroscopy, thermogravimetric analysis (TGA) and photoluminescence (PL) measurements in detail. TGA shows that the decomposition temperature of the complex is up to 320 °C. PL measurement results indicate that the Eu(III) complex exhibit intense red-emission with the characteristic of europium ion. Red LED device was successfully fabricated by employing the complex onto 380 nm-emitting InGaN chip, which shows that the complex can act as red phosphor in combination with 380 nm-emitting chips.

Syntheses, crystal structure and luminescent properties of cadmium complexes based on 2,6-bis(1-phenylbenzimidazol-2-yl)pyridine.

Two cadmium complexes, Cd(bpbp)Cl(2) (complex 1) and [Cd(bpbp)(2)](ClO(4))(2) (complex 2), based on 2,6-bis(1-phenylbenzimidazol-2-yl)pyridine (bpbp), were synthesized and characterized by X-ray single crystal structure analyses. For complex 1: crystal system, monoclinic, space group, C2/c, a=27.427(3)Å, b=13.4495(15)Å, c=14.8381(17)Å, ß=106.635(2)°, V=5244.4(10)Å(3), Z=8. It is a neutral complex. The Cd(II) ion distorted trigonal bipyramidal geometry is five-coordinated by three nitrogen atoms from ligand (bpbp) and two chlorine ions. For complex 2: crystal system, triclinic, space group, P-1, a=13.4791(15)Å, b=13.8506(16)Å, c=16.5839(19)Å, α=94.202(2)°, ß=106.948(2)°, γ=94.872(2)°, V=2935.3(6)Å(3), Z=2. It is an ionic complex. The Cd(II) ion octahedral geometry is six-coordinated by six nitrogen atoms from two ligand (bpbp). Both complexes emit blue luminescence with emission peaks at 420 and 430 nm in solid state and with emission peaks at 415 and 425 nm in DMF solution. In complex 1 absorption spectra, there is not only the free ligand absorption peak at 310 nm, but also shows strong Cd-Cl charge transfer peak at 350 nm in DMF solution.

White-light emitting microtubes of mixed organic charge-transfer complexes.

Self-assembled microtubes of mixed charge-transfer (CT) complexes comprising TCNB and naphthalene can be constructed with pyrene as dopant by an etching-assisted CT-induced interaction. Highly efficient Förster resonance energy transfer (FRET) from the excited naphthalene-TCNB to pyrene-TCNB molecules is obtained in mixed CT complex microtubes. White-light emissive CT complex microtubes can be formed by adjusting the dopant concentration and serve as an active optical waveguide.

[Spontaneous abortion and changes of estrogen receptors and progesterone receptors in the endometria of patients with polycystic ovary syndrome].

OBJECTIVE: To explore the relationship between the spontaneous abortion and changes of estrogen receptors (ER) and progesterone receptors (PR) in the endometria of patients with polycystic ovary syndrome (PCOS). METHODS: Thirty-two patients who suffered PCOS combined with infertilitas feminis were enrolled in a experimental group,and 20 patients with tubal infertilitas feminis having the corresponding time period as a control group. The expressions of ER and PR in the endometria were observed by pathological examination and immunohistochemical staining. RESULTS: The expressions of ER and PR in the glands and interstitium of endometrial in the PCOS group were significantly lower than those of the tubal infertilitas feminis group (P=0.004,P=0.001). The expressions of ER and PR in the PCOS group in the glands organ and interstitium of endometrial among 3 different periods were not significantly different (P>0.05). The expressions of ER in the glands of endometrium in the spontaneous abortion group were significantly lower than those of the non-spontaneous abortion group (P=0.02), but there was no statistical difference between the two groups in the interstitium of endometria (P>0.05). The expression of PR in the glands interstitium of endometria showed no statistical difference between the spontaneous abortion group and the non-spontaneous abortion group (P>0.05). CONCLUSION: The decrease of ER and PR of endometrial in the PCOS patients, may be a reason for spontaneous abortion, and the cyclical irregularity of ER and PR in the PCOS patients is another cause of spontaneous abortion.

[Clinical analysis of 4 treatments for woman polycystic ovarian syndrome with infertility].

OBJECTIVE: To investigate the therapeutic effects of 4 different treatments for woman polycystic ovarian syndrome (PCOS) with infertility. METHODS: One hundred and twenty women PCOS with infertility were divided into 4 Groups : patients in Group 1 were directly treated with clomiphene (CC)/CC + human menopausal gonadotropin (HMG) + human chorionic gonadotropin (HCG) to accelerate ovulation; patients in Group 2 were treated with the same way as Group 1 after taking marvolon for 2 cycles; patients in Group 3 took marvolon for 2 cycles and metformin for 8 weeks, and then were treated the same as Group 1; patients in Group 4 were treated with laparosocopy. The body mess index (BMI), emmenia period, weight, volume of ovary, LH, and T were measured before and after the treatment in all patients. The cycle ovulatory rate and occurrence rate of luteinized unruptued follicle syndrome (LUFS) within 2 months and the pregnancy rate within 6 months after the treatment were also observed. RESULTS: In all patients, BMI, emmenia period, serum T, and serum LH decreased significantly (P <0.05 or 0.01). The body mess indexes were significantly lower in Group 2 and Group 3 than those in Group 4 and Group 1, and Group 4 was also lower than Group 1 (P < 0.05 or 0.01). There was no difference in emmenia period between the 4 groups (P = 0.289). The volumes of ovary were enlarged in Group 1, and they were shrunk in the residual groups, which was significantly lower in Group 4 than in Group 2 and 3 (P < 0.01). The cycle ovulation rates were 53%, 72 %, 78 %, and 76%; the pregnancy rates within 6 months were 20%, 47%, 50%, and 57%, respectively; and they were significantly higher in the Group 2, 3 and 4 than in Group 1 (P <0.01). The occurrence rates of LUFS were 32%, 16%, 15%, and 13%, and they were significantly lower in Group 2, 3 and 4 than in Group 1 (P <0. 01). CONCLUSION: The effects of marvolon or marvolon and metformin are the same as those of laparoscopy not only in controlling the symptoms of PCOS, but also in increasing the cycle ovulation rate, pregnancy rate within 6 months, and decreasing the occurrence rate of LUFS. The symptoms of PCOS can be controlled better, but the cycle ovulation rate and pregnancy rate within 6 months can not be improved when clomiphene is used alone.