Research concerning CH3NH3PbI3 solar cells (SCs) has attracted great attention. However, the material’s critical dispersion relationships, i.e. refractive index and extinction coefficient, n(λ) k(λ), as functions of λ, have been little studied. Without this knowledge, it will be difficult to quantitively investigate optical properties SCs. We studied k(λ) with spectroscopic ellipsometry. The film was fabricated by dual-source evaporation, surface roughness investigated facilitate SE...

In this report, we find multilayered graphene, which has good transparency, conductivity and suitable work function, can be used as the anode for organic light emitting device. Our device structure is Al/glass/multilayered graphene/V2O5/NPB/CBP:(ppy)2Ir(acac)/Bphen/Bphen:Cs2CO3/Sm/Au. The maximum luminance efficiency power reach 0.75 cd/A 0.38 lm/W, respectively. We believe that by optimizing hole density uniforming thickness of graphene anode, remarkably increased in future.

A high-performance NOT logic gate (inverter) was constructed by combining two identical n-channel metal−semiconductor field-effect transistors (MESFETs) made on a single CdS nanowire (NW). The inverter has voltage gain as high 83, which is the highest reported so far for inverters one−dimensional nanomaterials. MESFETs used in circuit show excellent transistor performance, such on/off current ratio (∼107), low threshold (∼−0.4 V), and subthreshold swing (∼60 mV/dec). With assembly of three...

Visible electroluminescence (EL) has been reported from semitransparent Au film/extra thin Si-rich silicon oxide film/p-Si diodes at room temperature. The films, with thickness of about 40 Å, were grown using the magnetron sputtering technique. At forward bias 4 V, EL spectra peak energy 1.9 eV and full width half maximum 0.5 can be observed such extra films having not annealed. shows a small red shift under low but does again when increasing further. Annealing 800 °C, widen show several...

Nano-Schottky diodes and nanometal-semiconductor field-effect transistors (MESFETs) on single CdS nanobelts (NBs) have been fabricated studied. The Au/CdS NB Schottky very low reverse current density ( approximately 3.0 x 10-5 A.cm-2 at -10 V bias) the highest on/off ratio (approximately 108) reported so far for nano-Schottky diodes. MESFETs exhibit n-channel normally (depletion) mode, threshold voltage -1.56 V), high transconductance 3.5 microS), subthreshold swing 45 mV/dec), 2...

High quality n-type CdS nanobelts (NBs) were synthesized via an in situ indium doping chemical vapor deposition method and fabricated into field effect transistors (FETs). The electron concentrations mobilities of these NBs are around (1.0×1016–3.0×1017)∕cm3 100–350cm2∕Vs, respectively. An on-off ratio greater than 108 a subthreshold swing as small 65mV∕decade obtained at room temperature, which give the best performance nanowire/nanobelt FETs reported so far. NB∕p+-Si heterojunction light...

We have demonstrated for the first time that under suitable gate biases, single CdS nanobelt (NB) metal-semiconductor field-effect transistors (MESFETs) can serve as high-performance photodetectors. When a voltage near to threshold of MESFET illumination is supplied, NB MESFET-based photodetectors exhibit high photosensitivity, such ultrahigh photoresponse ratio (Ilight/Idark ≈ 2.7 × 106) (among best values reported so far NB/NW photodetectors), current responsivity (∼2.0 102 A/W), external...

We develop a simple and scalable graphene patterning method using electron-beam or ultraviolet lithography followed by lift-off process. This method, with the merits of: high pattern resolution alignment accuracy, free from additional etching harsh process, universal to arbitrary substrates, compatible Si microelectronic technology, can be easily applied diverse graphene-based devices, especially in array-based applications, where large-scale patterns are desired. have this fabricate CdSe...

SiQDs with an average diameter of 2.6 ± 0.5 nm are used as the light emitting material in high-efficiency inverted structure diodes.

Ultraviolet (UV) light emission with almost the same peak wavelengths from thermally oxidized porous silicon (OPS) (340, 355, and 370 nm) SiO2 powder 350, has been observed. Photoluminescence excitation spectra of OPS without Si nanoscale particles (SNP) those are very similar, however, different SNP. Three types luminescence centers around 350 nm responsible for UV emission, photoexcitation in SNP occurs as well oxide layers covering

We report novel graphene nanoribbon (GNR)/semiconductor nanowire (SNW) heterojunction light-emitting diodes (LEDs) for the first time. In device, GNR and SNW have face-to-face contact with each other, which has merits of a larger active region smaller series resistance, may benefit high-efficiency electroluminescence even electrically driven lasers in future. ZnO, CdS, CdSe NWs were employed our case. At forward biases, GNR/SNW heterjunction LEDs could emit light wavelengths varying from...

There is much debate about the photoluminescence (PL) mechanisms of nanoscale Si/Si oxide systems containing oxidized porous silicon and a nanoscale-Si-particle (NSP)---embedded Si deposited by chemical vapor deposition, sputtering, or Si-ion implanting into oxide. In this paper, we suggest that two competitive processes, namely, quantum confinement (QC) process confinement-luminescence center (QCLC) process, take place in PL. The photoexcitation occurs NSPs for both while photoemission...

A systematic study of the dependence photoluminescence from porous silicon (PS) on oxidation extent and measurement temperature is given. Oxidation PS samples at room up to 200 \ifmmode^\circ\else\textdegree\fi{}C results in spectra with maxima centered around 1.7 eV. The shift 10--300 K always toward 1.7-eV position. These conflict predictions quantum confinement model for luminescence, but can be explained by assuming that several types luminescence center outside nanoscale Si units are...

High quality single-crystal CdS nanowire (NW) networks have been synthesized on Si(111) substrates via the chemical vapour deposition method. X-ray diffraction and selected area electron show that NWs in grow along directions their (0001) crystal planes are parallel to substrates. Room-temperature photoluminescence (PL) spectra of single dominated by a near-band-edge emission free from deep-level defect emissions. The PLs resulting free-exciton bound-exciton recombinations detected at 77 K....

Orthorhombic phase Bi2S3 micro/nanocrystals with various morphologies have been successfully synthesized via a facile one-step hydrothermal approach without any templates or surfactants. The formation mechanisms of the proposed on basis experimental results. photoresponse properties using nanorods as representative system show significantly enhanced conductivity and steady fast response time 177.1 ms, indicating its potential application in high-speed high-sensitivity photodetectors...

A new method to employ graphene as top electrode was introduced, and based on that, fully transparent quantum dot light-emitting diodes (T-QLEDs) were successfully fabricated through a lamination process. We adopted the widely used wet transfer bilayer (BG) polydimethylsiloxane/polyethylene terephthalate (PDMS/PET) substrate. The sheet resistance of reduced ∼540 Ω/□ transferring BG for 3 times PDMS/PET. T-QLED has an inverted device structure glass/indium tin oxide (ITO)/ZnO...

Photoluminescence and electroluminescence from a Si/SiO2 superlattice have been measured. They show similar characteristics exhibit an inhomogeneously broadened photoluminescence band peaked at 2.06 eV. The excitation spectrum indicates that excitations occur in the Si layers. insensitivity of luminescence decay to temperature wavelength suggests originates transitions between localized defect states. These states are most likely residing interfaces, because there should be significant...

Single crystalline zincblende p-ZnTe nanowires (NWs) were synthesized via the vapour phase transport method. Based on either as-grown or Cu doped ZnTe NWs, single NW field effect transistors fabricated and they used to study electrical properties of NWs. Electrical measurements show that NWs are p-type very high resistivity. After 30 min immersion in Cu(NO3)2 solution, their conductivity can be increased by about three orders magnitude. The hole concentrations could controlled a range from...

Cd-enriched ambient, high quality n-type CdSe nanobelts (NBs) with various electron concentrations (from ∼1016 to 1018 cm−3), which can meet different device requirements, were synthesized via the chemical vapor deposition (CVD) method. The mobilities are much higher than those reported previously for one-dimensional (1D) nanostructures. High performance single NB field effect transistors (NB-FETs) and NB/p+-Si heterojunction light emitting diodes (HLEDs) fabricated studied. NB-FETs have...

Schottky junction photovoltaic (PV) devices were fabricated on single CdS nanobelts (NBs). Au was used as the contact, and In/Au ohmic contact to NB. Typically, exhibits a well-defined rectifying behavior in dark with rectification ratio greater than 10(3) at +/- 0.3 V; PV device clear an open circuit photovoltage of about 0.16 V, short current 23.8 pA, maximum output power 1.6 pW, fill factor 42%. Moreover, can be multiplied by connecting two or more devices, made NB, parallel series. This...

A 1.55-μ m hybrid InGaAsP-Si laser was fabricated by the selective-area metal bonding method. Two Si blocking stripes, each with an excess-metals accommodated space, were used to separate optical coupling area and areas. In such a structure, air gap between InGaAsP structure waveguide has been reduced be negligible. The operates threshold current density of 1.7 kA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> slope efficiency 0.05...