Partial Cap Research Articles

Breakdown voltage enhancement and specific on-resistance reduction in depletion-mode GaN HEMTs by co-modulating electric field

In this letter, a depletion-mode GaN high electron mobility transistors (GaN HEMTs) with high breakdown voltage and low on-resistance are designed and experimentally demonstrated. It combines the gate field plate and partial unintentionally doped GaN (u-GaN) cap layer (gate field plate and partial u-GaN cap HEMTs: GPU-HEMTs) to co-modulate the surface electric field distribution, which results in the electric field peak being far away from the gate edge, thus improving the breakdown voltage and decreasing the on-resistance. The optimized GPU-HEMTs exhibit a larger output current (I DS) of 495 mA mm−1 and a correspondingly smaller specific on-resistance of 4.26 mΩ·cm2. Meanwhile, a high breakdown voltage of 1044 V at I DS = 1 mA mm−1 compared to the conventional GaN HEMTs of 633 V was obtained. This approach is highly effective in simultaneously optimizing the breakdown voltage and the specific on-resistance of GaN HEMTs, while maintaining a large output current.

CryoEM structure and Alphafold molecular modelling of a novel molluscan hemocyanin.

Hemocyanins are multimeric oxygen transport proteins present in the blood of arthropods and molluscs, containing up to 8 oxygen-binding functional units per monomer. In molluscs, hemocyanins are assembled in decamer 'building blocks' formed of 5 dimer 'plates', routinely forming didecamer or higher-order assemblies with d5 or c5 symmetry. Here we describe the cryoEM structures of the didecamer (20-mer) and tridecamer (30-mer) forms of a novel hemocyanin from the slipper limpet Crepidula fornicata (SLH) at 7.0 and 4.7 Å resolution respectively. We show that two decamers assemble in a 'tail-tail' configuration, forming a partially capped cylinder, with an additional decamer adding on in 'head-tail' configuration to make the tridecamer. Analysis of SLH samples shows substantial heterogeneity, suggesting the presence of many higher-order multimers including tetra- and pentadecamers, formed by successive addition of decamers in head-tail configuration. Retrieval of sequence data for a full-length isoform of SLH enabled the use of Alphafold to produce a molecular model of SLH, which indicated the formation of dimer slabs with high similarity to those found in keyhole limpet hemocyanin. The fit of the molecular model to the cryoEM density was excellent, showing an overall structure where the final two functional units of the subunit (FU-g and FU-h) form the partial cap at one end of the decamer, and permitting analysis of the subunit interfaces governing the assembly of tail-tail and head-tail decamer interactions as well as potential sites for N-glycosylation. Our work contributes to the understanding of higher-order oligomer formation in molluscan hemocyanins and demonstrates the utility of Alphafold for building accurate structural models of large oligomeric proteins.

Congenital absence of the left pericardium: a case report

BackgroundCongenital absence of the pericardium (CAP) is rare in clinical practice, the symptoms vary among patients, and most doctors do not have enough knowledge of the condition. Most reported CAP cases are incidental findings. Therefore, this case report aimed to present a rare case of left partial CAP that presented with non-specific, possibly cardiac-related symptoms.Case presentationThe patient, male, 56 years old, Asian, was admitted on March 2, 2021. The patient complained of occasional dizziness in the past week. The patient was suffering from hyperlipidemia and hypertension (stage 2), both untreated. The patient reported chest pain, palpitations, discomfort in the precordium, and dyspnea in the lateral recumbent position after strenuous activities, all of which started when he was about 15 years old. ECG showed sinus rhythm, 76 bpm, premature ventricular beats, incomplete right bundle branch block, and clockwise rotation of the electrical axis. Most of the ascending aorta could be detected in the parasternal intercostal space 2–4 by transthoracic echocardiography in the left lateral position. Chest computed tomography revealed the absence of pericardium between the aorta and the pulmonary artery, and part of the left lung was extending into the space. No changes in his condition have been reported up to now (March 2023).ConclusionsCAP should be considered when multiple examinations suggest heart rotation and a large moving range of the heart in the thoracic cavity.

Size of the zero set of solutions of elliptic PDEs near the boundary of Lipschitz domains with small Lipschitz constant

Let Omega subset {mathbb {R}}^d be a C^1 domain or, more generally, a Lipschitz domain with small Lipschitz constant and A(x) be a d times d uniformly elliptic, symmetric matrix with Lipschitz coefficients. Assume u is harmonic in Omega , or with greater generality u solves {text {div}}(A(x)nabla u)=0 in Omega , and u vanishes on Sigma = partial Omega cap B for some ball B. We study the dimension of the singular set of u in Sigma , in particular we show that there is a countable family of open balls (B_i)_i such that u|_{B_i cap Omega } does not change sign and K backslash bigcup _i B_i has Minkowski dimension smaller than d-1-epsilon for any compact K subset Sigma . We also find upper bounds for the (d-1)-dimensional Hausdorff measure of the zero set of u in balls intersecting Sigma in terms of the frequency. As a consequence, we prove a new unique continuation principle at the boundary for this class of functions and show that the order of vanishing at all points of Sigma is bounded except for a set of Hausdorff dimension at most d-1-epsilon .

Slip of submerged two-dimensional liquid-infused surfaces in the presence of surfactants

Using numerical simulations, we investigate the effects of Marangoni stresses induced by surfactants on the effective slip length of liquid-infused surfaces (LIS) with transverse grooves. The surfactants are assumed soluble in the external liquid shearing the surface and can adsorb onto the interfaces. Two different adsorption models are used: a classical Frumkin model and a more advanced model that better describes the decrease of surface tension for minuscule concentrations. The simulations show that LIS may face even more severe effects of surfactants than previously investigated superhydrophobic surfaces. Constructing an analytical model for the effective slip length, we can predict the critical surfactant concentration for which the slip length decreases significantly. This analytical model describes both adsorption models of LIS on a unified framework if properly adjusted. We also advance the understanding of when surfactant advection gives rise to highly skewed interfacial concentrations: the so-called partial stagnant cap regime. To a good approximation, this regime can only exist below a specific surfactant concentration given by the Marangoni number and the strength of the surfactants.

Suggestion of ultimate strength formulas of partial frame pile cap composed of exterior column, foundation beam and pile

Currently, there is no research and few valid experiments of pile caps. And shear failure mechanism of a pile, exterior column and foundation beam and pile caps in RC structure is not resolved yet under bi-lateral loading. Therefore, a performance evaluation method based on mechanical behaviour for pile caps has not been established. First, the fracture type was specified from the experimental results. Secondary, the ultimate strength formula of the pile cap was proposed based on the previous experimental results. It is a theoretical formula based on the truss-arch theory. It was confirmed that this formula can accurately evaluate the ultimate strength of the pile cap.

Experimental Results for AlGaN/GaN HEMTs Improving Breakdown Voltage and Output Current by Electric Field Modulation

A depletion-mode AlGaN/GaN high electron mobility transistors (HEMTs) have been proposed in this article with the partial GaN cap, which applies the electric field modulation effect to optimize the surface electric field and two-dimensional electron gas (2DEG) distribution. The 2DEG density under the partial GaN cap is reduced due to the polarization effect formed by the partial GaN cap and AlGaN layers. The surface electric field is reshaped by the electric field modulation effect due to the partial GaN cap, featuring an extra electric field peak far away from the gate edge, which, therefore, improves the breakdown voltage (BV). Moreover, the output current ( ${I}_{\text {DS}}$ ) is also improved slightly resulting from the increased mobility of 2DEG, which compensates for the decrease in the 2DEG density. The experimental BV is increased greatly from 378 V for the conventional AlGaN/GaN HEMTs to 656 V for the depletion-mode partial cap layer AlGaN/GaN HEMTs because of the optimized surface electric field by the electric field modulation effect. The maximum output current ( ${I}_{\text {max}}$ ) is increased from 538 to 558 mA/mm. It is concluded that the BV can be improved significantly and ${I}_{\text {DS}}$ increased slightly for AlGaN/GaN HEMTs by the electric field modulation technique using the partial GaN cap, which optimizes the BV and specific ON-resistance ( ${R}_{ \mathrm{\scriptscriptstyle ON}, \text {sp}}$ ) simultaneously.

Molecular detection and phylogenetic analysis of Porcine circovirus 4 in Henan and Shanxi Provinces of China.

Porcine circovirus 4 (PCV4), a new circovirus with a distinct relationship to other circoviruses, was identified in 2019 in several pigs with severe clinical disease in Hunan Province, China. To investigate the epidemic profile and genetic diversity of the virus, 63 clinical samples were collected from 24 different pig farms in 14 cities in Henan and Shanxi Provinces, China, between February 2018 and December 2019, and the partial Cap gene of PCV4 was amplified by PCR. Among the 63 samples, 16 (25.40%) were positive for PCV4, and 50% (12/24) of the pig farms were positive for PCV4. PCV4 was detected in samples from pigs with different clinical presentations. One PCV4 strain (Henan-LY1-2019) was sequenced in this study, and shared 98.4% genomic nucleotide identity with PCV4 strain HNU-AHG1-2019 (accession no. MK986820) detected on a pig farm in Hunan Province in 2019. A phylogenetic analysis based on the genomes of Henan-LY1-2019 and 31 reference strains showed that the Henan-LY1-2019 strain together with PCV4 strain HNU-AHG1-2019 was grouped in a relatively independent sub-branch, and separated from other viruses in the genus Circovirus. The results of this study extend our understanding of the molecular epidemiology of PCV4.

Distribution and genetic diversity of adeno-associated viruses in bats from coastal areas of Southeast China

Bats are associated with several important zoonotic viruses from different families. One example includes adeno-associated viruses (AAVs), that are extensively detected in several animals, especially primates. To understand AAVs distribution and genetic diversity in the coastal areas of Southeast China, a total of 415 intestine samples were mostly collected from two provinces of southeast China, i.e., Zhejiang and Fujian province. Intestine samples from five bat species were collected for AAVs detection. The average prevalence rate for AAV detection among these samples was 18.6% (77 positives out of 415 samples) and ranged from 11.8 to 28.9% between the five bat species. This suggests that AAVs are widely distributed in diverse bat populations in southeast coastal areas of China. Based on the genome sequence of bat adeno-associated virus-CXC1(BtAAV-CXC1) from one AAV-positive sample, the genetic diversity of the detected AAVs were assessed and analyzed. Phylogenetic analysis revealed that BtAAV-CXC1 was comparatively distant to other major AAVs from mammals and non-mammals, with only a 52.9~64.7% nucleotide identity. However, they were phylogenetically closer to Rhinolophus sinicus bat adeno-associated virus (Rs-BtAAV1), with a 74.5% nt similarity. Partial analysis of the rep and cap overlapping open reading frame (ORF) sequences from bat AAV samples revealed 48 partial rep sequences and 23 partial cap sequences from positive samples shared 86.9 to 100% and 72.3 to 98.8% nucleotide identities among themselves, respectively. This suggests that the detected AAVs had a distinctly high genetic diversity. These findings led us to conclude that diverse AAVs may be widely distributed in bat populations from the southeast regions of China.

A novel AlGaN/GaN Schottky barrier diode with partial p-AlGaN cap layer and recessed dual-metal anode for high breakdown and low turn-on voltage

A novel AlGaN/GaN Schottky barrier diode with partial p-AlGaN cap layer and recessed dual-metal anode is proposed and investigated by TCAD simulation in this work. By utilizing this structure, the device can achieve both enhanced reverse blocking capacity and superior forward performance. The operating mechanism of the partial p-AlGaN cap layer is analyzed. Carriers underneath the partial cap layer are depleted, and the electric field is redistributed, leading to a lower reverse leakage current and a higher breakdown voltage. Additionally, the recessed dual-metal anode allows the device to turn on at a low forward bias. The effect of the length and thickness of partial p-AlGaN cap layer on the reverse and forward performance has been further investigated, respectively. The optimized device shows excellent performance with a breakdown voltage of 2461 V, a turn-on voltage of 0.43 V, and the highest Baliga’s figure of Merit of 1738 MW cm−2. The fabrication issues of the proposed device have also been presented.

Analytical model of AlGaN/GaN HEMTs with a partial GaN cap layer

In this paper, a two-dimensional analytical model of AlGaN/GaN HEMTs with a partial GaN cap layer is developed. Under two assumptions of complete depletion and incomplete depletion, the analytical expressions for the channel potential and electric field distributions are obtained on the basis of Poisson's equation. The dependences of the channel potential and electric field distributions on various thicknesses and lengths of the partial GaN cap layer are demonstrated. The analytical model is verified in comparison with the ISE TCAD simulation. A fair consistency between the analytical and numerical results indicates the validity of the proposed analytical model. This method provides a reference to model other different GaN-based power devices.

Detection and phylogenetic analysis of porcine circovirus type 3 in central China.

Porcine circovirus type 3 (PCV3) is the pathogen responsible for a new infectious disease that was first reported in 2016 in the United States. To further investigate the epidemic profile and genetic diversity of the virus, one hundred and seventy clinical samples (110 tissue samples and 60 serum samples) were collected from 41 different pig farms in 14 cities in central China, and a SYBR Green I-based quantitative real-time PCR method was developed to detect PCV3. The partial cap genes of four field strains from four different farms were sequenced and analysed. The results showed the detection limit was 2.19×101 genome copies/μl. Fifty-three of 170 samples were detected as positive for PCV3, giving a PCV3-positive rate of 31.18%, with 48.78% (20/41) of pig farms harbouring PCV3, which varied from 20% to 42.86% between 2013 and 2017. PCV3 could be detected in samples from pigs with different clinical presentations, and the PCV3-positive rates varied for these different clinical presentations. The partial capsid genes of four PCV3 strains (designated YZ, LY-03, NY and SP) shared 96.3%-99.4% nucleotide identity with those available in GenBank. Phylogenetic analysis based on the capsid gene of 32 PCV3 strains showed that the four PCV3 strains in this study were clustered with the China/GD2016 and South Korea Ku-1606 strains. The results of this study will aid our understanding of the molecular epidemiology of PCV3.

Enhancement‐mode AlGaN/GaN HEMTs with optimised electric field using a partial GaN cap layer

To optimise the surface electric field distribution of conventional enhancement-mode AlGaN/GaN high electron mobility transistors (HEMTs), a novel enhancement-mode AlGaN/GaN HEMT with a P-type GaN gate is proposed for the first time in this work. The proposed AlGaN/GaN HEMT has an optimised surface electric field using a partial GaN cap layer. Through the introduction of the partial GaN cap layer in the region between the gate and drain electrodes, a two-dimensional electron gas (2DEG) density reduction is obtained due to the polarisation effect. By modifying the concentration distribution of high-density 2DEG, the electric field modulation effect is applied, which introduces a new electric field peak. The high electric field peak near the gate edge of the drain side effectively decreases, and the electric field is more uniformly redistributed from the gate to the drain regions. The simulation results show that the breakdown voltage can be improved by 192.2% compared with that of the conventional enhancement-mode AlGaN/GaN HEMTs.

Characteristic analysis of new AlGaN/GaN high electron mobility transistor with a partial GaN cap layer

In order to reduce the high electric field peak near the gate edge and optimize the non-uniform surface electric field distribution of conventional AlGaN/GaN high electron mobility transistor (HEMT), a novel AlGaN/GaN HEMT with a partial GaN cap layer is proposed in this paper. The partial GaN cap layer is introduced at the top of the AlGaN barrier layer and is located from the gate to the drain drift region. A negative polarization charge at the upper hetero-junction interface is induced, owing to the polarization effect at the GaN cap layer and AlGaN barrier layer interface. Hence, the two dimensional electron gas (2DEG) density is reduced. The low-density 2DEG region near the gate edge is formed, which turns the uniform distribution into a gradient distribution. The concentration distribution of 2DEG is modified. Therefore, the surface electric field distribution of AlGaN/GaN HEMT is modulated. By the electric field modulation effect, a new electric field peak is produced and the high electric field peak near the gate edge of the drain side is effectively reduced. The surface electric field of AlGaN/GaN HEMT is more uniformly redistributed in the drift region. In virtue of ISE-TCAD simulation software, the equipotential and the surface electric field distribution of AlGaN/GaN HEMT are obtained. For the novel AlGaN/GaN HEMT employing a partial GaN cap layer, the 2DEG is completely depleted from the gate to the drain electrodes, arising from the low-density 2DEG near the gate edge, while the 2DEG is partly depleted for the conventional AlGaN/GaN HEMT. The surface electric field distribution of the conventional structure is compared with the one of the novel structures with partial GaN cap layers of different lengths at a fixed thickness of 228 nm. With increasing length, the new electric field peak increases and shifts toward the drain electrode, and the high electric field peak on the drain side of the gate edge is reduced. Moreover, the breakdown voltage dependence on the length and thickness of the partial GaN cap layer is achieved. The simulation results exhibit that the breakdown voltage can be improved to 960 V compared with 427 V of the conventional AlGaN/GaN HEMT under the optimum conditions. The threshold voltage of AlGaN/GaN HEMT remains unchanged. The maximum output current of AlGaN/GaN HEMT is reduced by 9.2% and the specific on-resistance is increased by 11% due to a 2DEG density reduction. The cut-off frequency keeps constant and the maximum oscillation frequency shows an improvement of 12% resulting from the increased output resistance. The results demonstrate that the proposed AlGaN/GaN HEMT is an attractive candidate in realizing the high-voltage operation of GaN-based power device.

On partial CAP∗-subgroups of finite groups

A subgroup [Formula: see text] of a finite group [Formula: see text] is said to be a partial [Formula: see text]-subgroup of [Formula: see text] if there exists a chief series [Formula: see text] of [Formula: see text] such that [Formula: see text] either covers or avoids each non-Frattini chief factor of [Formula: see text]. In this paper, we study the influence of the partial [Formula: see text]-subgroups on the structure of finite groups. Some new characterizations of the hypercyclically embedded subgroups, [Formula: see text]-nilpotency and supersolubility of finite groups are obtained.

辽西低凸起中北段潜山油气藏泥岩盖层封闭能力评价

为综合评价辽西低凸起泥岩盖层封闭能力，统计分析了辽西低凸起中北段潜山基础井资料，表明辽西低凸起潜山盖层主要由东营组和沙河街组泥岩盖层组成，其中以东营组泥岩盖层为区域性盖层，沙一段沙二段和沙三段泥岩盖层在JZ20-2、JZ25-1S潜山有分布，为局部盖层。选取泥质含量、突破压力、超压压力系数等参数研究微观特征，研究表明辽西低凸起潜山盖层主要存在泥岩毛细管压力封盖和超压封盖两种类型的微观机理，其中超压封盖主要分布在低凸起中北部JZ25-1S地区与JZ20-2地区。综合评价辽西低凸起中北段泥岩盖层封闭能力。结果表明：辽西低凸起中北段盖层以中等、好为主，好盖层分布较广。通过分析盖层与已发现油气藏关系，辽西低凸起中北段已发现油气分布在中等及以上盖层区域内，表明中等封盖能力的潜山盖层就能很好的封闭潜山油气。 In order to comprehensively evaluate low bulge mudstone caprock sealing ability, the data of buried hill basic well in Liaoxi low uplift are statistically analyzed. It shows that Liaoxi low uplift buried hills cover layer is mainly composed of dongying group and the shahejie formation. Among them, mudstone caprock of Dongying formation is a regional cap rock. And Sha 1, Sha 2 and Sha 3 mudstone cover are distributed in the JZ20-2, JZ25-1s buried hill, which are partial cap rocks. The parameters of shale content, breakthrough pressure and overpressure pressure coefficient were selected to study the microscopic features. The results showed that there were mainly two types of micro-mechanisms: Mudstone capillary pressure cap and overpressure sealing system. Overpressure sealing system is mainly distributed in low rising in north-central JZ25-1s region and the JZ20-2. A comprehensive evaluation of the sealing ability of mudstone cover in the northern section of Liaoxi low uplift was made. The results showed that the top layer of the northern section of the low bulge in the Liaoxi low uplift was medium and good, and the distribution of the good cover was wide. By analyzing the relationship between cap rock and reservoir that had been found, and the oil and gas that had been found in the medium and above cover area, which showed that the buried caprocks with medium cap ability can well seal the buried hill oil and gas.

SU‐G‐JeP3‐11: Use of an Easily‐Modified Simple Phantom to Perform the Daily and Monthly Localization QA Tasks for a Video‐Based Surface Imaging System

Purpose:To describe a simple, easily fabricated, Styrofoam phantom used in conjunction with a commonly available OBI phantom, to QA a video‐surface imaging system according to TG147, using minimal effort.Methods:Styrofoam, a common packaging material, reflects the speckled AlignRT light very well. A Styrofoam block was used as a partial cap to attach onto a standard Varian Marker Match phantom. The cap was engraved with two sets crosshairs on each surface, one at the ‘zero’(center) and the other an ‘off‐centered’ position, 2 cm in all three orthogonal directions. A reference image is obtained at ‘zero’ position. For the daily test, static localization check is performed by aligning the phantom with room lasers at ‘off‐centered’ position and then the couch is shifted to match the ‘zero’ with the lasers. For the monthly test, plate calibration is recommended to define a relationship between an image point on the camera and that of the isocenter in the treatment room. Static localization accuracy is checked using a hidden‐target test, which is an extension of daily static localization procedure. The phantom positioned at ‘off‐centered’ is shifted to make the readings 0.0 cm for all orientations. The location of the hidden target is then verified by taking orthogonal kV images or CBCT.Results:The AlignRT tests required by TG147 are quite similar to those performed on on‐board imaging (OBI). Overall alignment of the system is maintained with RMS < 1 mm and any potential problems were identified. The system's static location is maintained within ± 1 mm. The same accuracy can be obtained for a monthly hidden target test which is integrated with an OBI QA.Conclusion:A customized phantom is tested and a routine QA program for surface‐imaging system is introduced. By dealing with a single phantom, the procedure can achieve similar goals efficiently.

Hydrocarbon Geology Characteristics and Oil & Gas Resource Potential in the Afghan-Tajik Basin

The Afghan-Tajik Basin is an intermontane depression between the mountain ranges of Gissar and Pamirs, and Jurassic system and Tertiary system are rich in large oil & gas resources. In order to assure sustainable supply of oil & gas from Central Asia, we deeply researched hydrocarbon geology characteristics and resource potentials. The basin belongs to paralic sedimentary environment, and develops 3 sedimentary strata: Jurassic, Cretaceous, and Tertiary. Afghan-Tajik Basin develops 3 main source rocks including clastic rocks of Jurassic, carbonate rocks of Cretaceous and mudstone rocks of Eocene. The basin develops 2 plays: Jurassic-Cretaceous play is gas containing one, and Tertiary play is oil containing one. Plaster stone and salt rock of upper Jurassic are regional cap rocks of Jurassic-Cretaceous gas pool, and creaming mudstone and muddy limestone of Cretaceous and Tertiary are regional or partial cap rocks. Migration and accumulation of hydrocarbon occur in the late Cretaceous and early Pliocene epoch. Afghan-Tajik Basin has larger exploration potentials, and residual resources are 2.4¡Á108t. The potential zones are as follows, south part of basin, oil-gas structures of post-salt, reef limestone of pre-salt, and litho-stratigraphic traps.

Rim formation on non-elongated InAs quantum dots grown by partial cap and annealing process at low temperature

We have used atomic force microscopy to study in detail the shape of InAs quantum dots (QDs) grown on GaAs (001) substrates. The QDs are fabricated by partial capping and a subsequent annealing process at low temperature. We observe circular, non-elongated QDs, with rim structures on top. The majority of the QDs located on a step edge have an anisotropic rim structure with a crescent shape, whereas approximately 50% of QDs located on terraces have isotropic rim structures with a ring shape. These results indicate that the rims of non-elongated QDs are not always isotropic, and the formation of an isotropic or anisotropic rim structure is dependent on the location of the QD.

Effects of growth temperature of partial GaAs cap on InAs quantum dots in In‐flush process for single dot spectroscopy

AbstractWe have investigated effects of growth temperature of partial GaAs cap (Tcap) on InAs quantum dots (QDs) in indium‐flush (In‐flush) process with atomic force microscopy (AFM) and micro photoluminescence (μ‐PL) measurements. Tcap in In‐flush process are varied from 385 °C to 485 °C as an experimental parameter. In order to investigate the effects of Tcap on structural property of single InAs QD, shape of QD in initial capping process are characterized by AFM measurements in air at room temperature. While isotropic shape of QDs is kept in low Tcap conditions below about 440 °C, in‐plane anisotropy of initial shape of QDs are increased with increasing of Tcap due to elongation to the [1$ \bar 1 $0] direction. μ‐PL measurements are performed at 7K for the investigation of the effects of Tcap on optical property in single InAs QDs. In low Tcap conditions from 410 °C to 435 °C, distinct emissions from excitonic states in single QDs are observed. In the same Tcap range, the AFM result shows that isotropic shape of QDs is kept. On the other hand, in high Tcap conditions above about 440 °C, indefinite peaks and broad emissions appear remarkably. Excitonic emissions which are observed in low Tcap range are hardly observed in this high Tcap range (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)