Applied Physics Express (APEX) is a letters journal devoted solely to rapid dissemination of up-to-date and concise reports on new findings in applied physics. It is published daily online and monthly for the printed version. The motto of APEX is high scientific quality and prompt publication. APEX is a sister journal of the Japanese Journal of Applied Physics (JJAP) and is published by IOP Publishing Ltd on behalf of the Japan Society of Applied Physics (JSAP).
This publication is partially supported by a Grant-in-Aid for Publication of Scientific Research Results from the Japan Society for the Promotion of Science.
Number 1, January 2015 (011001-019202)
From 2014, APEX will be published by IOP Publishing on behalf of The Japan Society of Applied Physics. All submissions and refereeing will continue to be handled by the APEX Editorial Office at The Japan Society of Applied Physics. To submit a paper to APEX, please connect to the editorial web site.
In the last 30 days
Shiro Kaneko et al 2014 Appl. Phys. Express 7 035102
Silicene or germanene is a monolayer honeycomb lattice made of Si or Ge, similar to graphene made of C. In this work, we have assessed the performance potentials of silicene nanoribbon (SiNR), germanene nanoribbon (GeNR), and graphene nanoribbon (GNR), which all have a sufficient band gap to switch off, as field-effect transistor (FET) channel materials. We have demonstrated that, by comparing at the same band gap of ∼0.5 eV, the GNR FET maintains an advantage over SiNR or GeNR FETs under an ideal transport situation, but SiNR and GeNR are attractive channel materials for high-performance FETs as well.
Cyril Pernot et al 2010 Appl. Phys. Express 3 061004
We report on the fabrication and characterization of AlGaN-based deep ultraviolet light-emitting diodes (LEDs) with the emission wavelength ranging from 255 to 280 nm depending on the Al composition of the active region. The LEDs were flip-chip bonded and achieved external quantum efficiencies of over 3% for all investigated wavelengths. Under cw operation, an output power of more than 1 mW at 10 mA was demonstrated. A moth-eye structure was fabricated on the back side of the sapphire substrate, and on-wafer output power measurement indicated a 1.5-fold improvement of light extraction.
Yuji Zhao et al 2011 Appl. Phys. Express 4 082104
We report a high-power blue light-emitting diode (LED) with a high external quantum efficiency and low droop on a free-standing (2021) GaN substrate. At a forward current of 20 mA, the LED showed a peak external quantum efficiency of 52% and an output power of 30.6 mW. In higher current density regions, the LED also showed outstanding performance, with droop ratios of 0.7% at 35 A/cm 2, 4.3% at 50 A/cm 2, 8.5% at 100 A/cm 2, and 14.3% at 200 A/cm 2. The output power and external quantum efficiency at 200 A/cm 2 were 266.5 mW and 45.3%, respectively.
Yongzhen Wu et al 2014 Appl. Phys. Express 7 052301
A uniform and pinhole-free hole-blocking layer is necessary for high-performance perovskite-based thin-film solar cells. In this study, we investigated the effect of nanoscale pinholes in compact TiO 2 layers on the device performance. Surface morphology and film resistance studies show that TiO 2 compact layers fabricated using atomic layer deposition (ALD) contain a much lower density of nanoscale pinholes than layers obtained by spin coating and spray pyrolysis methods. The ALD-based TiO 2 layer acts as an efficient hole-blocking layer in perovskite solar cells; it offers a large shunt resistance and enables a high power conversion efficiency of 12.56%.
Takahiro Fukui et al 2014 Appl. Phys. Express 7 055201
Nitrogen-vacancy (NV) centers in diamond have attracted significant interest because of their excellent spin and optical characteristics for quantum information and metrology. To exploit these characteristics, precise control of the orientation of the NV axis in the lattice is essential. Here we show that the orientation of more than 99% of the NV centers can be aligned along the  axis by chemical vapor deposition homoepitaxial growth on (111) substrates. We also discuss the alignment mechanisms. Our result enables a fourfold improvement in the magnetic field sensitivity and opens new avenues to the optimum design of NV center devices.
Takeo Oku et al 2014 Appl. Phys. Express 7 121601
TiO 2/CH 3NH 3PbI 3-based photovoltaic devices were fabricated. The microstructures of these devices were investigated by X-ray diffraction, transmission electron microscopy, and their calculations. Structure analysis indicated phase transformation of the perovskite structure from a tetragonal to a cubic system by annealing, which resulted in the improvement of photovoltaic properties of the devices. Effects of a multiple spin-coating method using a mixture solution were also investigated. The result showed an increase in the efficiencies of the devices, due to the microstructural change of the perovskite compound layers.
Hironori Katagiri et al 2008 Appl. Phys. Express 1 041201
Cu 2ZnSnS 4 (CZTS) thin film solar cells have been fabricated by co-sputtering technique using three targets of Cu, SnS, and ZnS. CZTS-based thin film solar cells over 6.7% efficiency were obtained for the first time by soaking the CZTS layer on the Mo coated soda-lime glass substrate in deionized water (DIW) after forming the CZTS layer. It was found that DIW-soaking had the effect of preferential etching, which eliminated selectively metal oxide particles in the CZTS layer, by electron probe X-ray micro analysis.
Ryugo Tero et al 2014 Appl. Phys. Express 7 077001
We provide direct evidence of plasma-induced pore formation in a cell membrane model system. We irradiated plasma on the basis of the dielectric barrier discharge onto a supported lipid bilayer (SLB). Observation with a fluorescence microscope and atomic force microscope revealed the formation of pores on the order of 10 nm–1 µm in size. Capturing these micropores in a fluid lipid membrane is a significant advantage of the SLB system, and quantitative analysis of the pores was performed. Stimulation with equilibrium chemicals (HNO 3 and H 2O 2) indicated that other transient active species play critical roles during the poration in the SLB.
Jong-Il Hwang et al 2014 Appl. Phys. Express 7 071003
We report on the optical properties of the InGaN-based red LED grown on a c-plane sapphire substrate. Blue emission due to phase separation was successfully reduced in the red LED with an active layer consisting of 4-period InGaN multiple quantum wells embedding an AlGaN interlayer with the Al content of 90% on each quantum well. The light output power and external quantum efficiency at a dc current of 20 mA were 1.1 mW and 2.9% with the wavelength of 629 nm, respectively. This is the first demonstration of a nitride-based red LED with the light output power exceeding 1 mW at 20 mA.
Jianping Liu et al 2014 Appl. Phys. Express 7 111001
Two-step growth was employed to grow GaN quantum barriers (QBs) in InGaN green LD structures. A cap layer was grown at the same temperature as an InGaN quantum well (QW), and the temperature was then raised by around 130 °C to grow GaN QBs. The effects of low-temperature-grown cap (LT-cap) layers on the optical properties and microstructures of green LD structures were investigated. It was found that the LT-cap layer with an optimal thickness can improve the luminescence homogeneity and suppress the thermal decomposition of InGaN QWs. C-plane ridge waveguide laser diodes lasing above 500 nm were realized.
This cloud represents the 50 most popular PACS codes from the latest 250 coded articles for this journal. The larger the code the more times it occurs in those 250 articles. Click on a code to link to the articles in that category.
42.55.Px 06.30.Bp 43.20.El 42.55.Tv 43.60.Tj 42.15.Eq 42.60.Lh 42.65.Pc 42.30.Va 42.25.Gy 32.80.Fb 07.85.Fv 42.70.Nq 05.40.Ca 51.50.+v 47.63.-b 42.82.Et 47.61.-k 42.70.Mp 42.55.Sa 42.30.Wb 33.50.Dq 07.60.Fs 42.60.Fc 42.55.Rz 42.55.Wd 42.30.-d 42.70.Qs 43.35.Mr 42.60.Jf 42.65.Re 42.82.Ds 42.79.Dj 42.40.Kw 42.81.Pa 07.07.Df 43.20.Ks 42.55.Xi 52.25.-b 42.72.Ai 43.20.Fn 43.20.Bi 07.60.-j 42.65.-k 47.60.Kz 42.65.Es 42.79.Gn 07.55.Ge 42.40.Lx 07.57.-c