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41.
文章对突变反型异质结的能带图、接触电势差和势垒区宽度进行了讨论和研究。同时,介绍了基于分子束外延(MBE)法生长的SiGe/Si结构的异质结双极晶体管(HBT)制造工艺,并给出了测试结果。 相似文献
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43.
A new type of ω-methoxy-functionalized oligo-(OCT) and poly-(PQ) hexylthiophene characterized by a tetrameric repeating unit was synthesized and characterized. The configurational regularity and the mean degree of functionalization per thiophenic ring, lower than in commonly synthesized PATs, permitted the obtainment of more ordered chain conformations especially in the solid (film) state. Solar cells based on OCT and PQ films (as p-donor polymeric layer) mixed with Single-walled Carbon Nanotubes (SWCNTs, used as electron-acceptor system) were prepared and investigated. A power conversion efficiency of 0.52% with a fill factor of 0.42, an open-circuit voltage of 0.48 V and a short-circuit current of 1.93 mA/cm2 under 70 mW/cm2 white light illumination is reported for the polymeric sample. The obtained performance is comparable with that of devices made with regioregular P3HT but the easiness of the monomer synthesis and polymer preparation, giving OCT and PQ with good yields, as well as the enhanced workability and filmability of the latters from diluted solutions of common organic solvents together with their low sensitivity to the environmental conditions (air oxygen, moisture, temperature) makes the synthesized materials very promising for the set-up of polymer photovoltaic cells. 相似文献
44.
本文首先简要介绍异质结双极晶体管(HBT)的结构和特点,接着评述HBT工艺技术发展现状、单元设计和目前制作的功率HBT的性能。 相似文献
45.
《International Journal of Hydrogen Energy》2022,47(11):7202-7213
The coupling of two-dimensional (2D) layered materials is an effective way to realize photocatalytic hydrogen production. Herein, using first-principles calculations, the photocatalytic properties of GaN/CNs heterojunctions formed by two different graphite-like carbon nitride materials and GaN monolayer are discussed in detail. The results show that the GaN/C2N heterojunction can promote the effective separation of photogenerated electron and hole pairs, which is attributed to its type-II band orientation and high carrier mobility. However, the low overpotential of GaN/C2N for photocatalytic hydrogen production limits the photocatalytic performance. On this basis, we adjust the CBM position of the GaN/C2N heterojunction by applying an electric field to enhance its hydrogen evolution capability. In addition, the GaN/g-C3N4 is a type-I heterojunction, which is suitable for the field of optoelectronic devices. This work broadens the field of vision for the preparation of highly efficient photocatalysts. 相似文献
46.
Weijie Zhao Jing Zhang Jiaqi Pan Wenhui Zhao Jiantao Niu Jianfeng Qiu Chaorong Li 《Ceramics International》2018,44(15):18337-18343
The 1D Ag3PO4 sensitized SrTiO3 nanowires are prepared by simple route of electrospinning-in situ deposition technique. The results of the thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive Spectrometer (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–Visible diffuse reflectance spectroscopy (UV–Vis) indicate that the Ag3PO4 nanoparticles has been deposited on the surface of the SrTiO3 nanowires successfully. Experimental results showed that compared with pure SrTiO3, the as-prepared 1D Ag3PO4 sensitized SrTiO3 nanowires exhibit obvious enhancement of photocatalytic performance and stability. Especially, the Ag3PO4/SrTiO3 (3AS sample) had a satisfactory photocatalytic activity for degrading methylene blue (MB) more than 98% under visible light irradiation. As to pure SrTiO3 and Ag3PO4, only 9.8% and 49% of MB was decomposed after 35?min irradiation respectively. Furthermore, the mechanism of the enhancing photocatalytic activity could be ascribed to the nano-heterojunction of the Ag3PO4/SrTiO3, the visible light response of the Ag3PO4, and the 1D structure of the nanowires. 相似文献
47.
Min Mao Jing Xu Lingjiao Li Sheng Zhao Xuanhao Li 《International Journal of Hydrogen Energy》2021,46(45):23190-23204
Using sunlight to catalyze water to produce H2 is a key technology to solve the problem of energy shortage. In this research, perovskite-type NiMnO3 and Ni3S4 was recombined through secondary hydrothermal treatment. The optimal hydrogen evolution for composite materials NiMnO3/Ni3S4is 3.76 μmol mg?1 h?1, that 3.7 and 4 times more than that of two monomer materials, respectively. After four cycles of catalytic experiments, proving the high efficiency and stability of the composite catalyst. The characteristics of fluorescence spectroscopy and electrochemistry have confirmed the existence of p-n heterostructures, the excellent catalytic performance is related to the built-in electric field (accelerating the separation and utilization of photocharges) generated by the combination of NiMnO3 and Ni3S4. Strengthening the performance of the catalyst by constructing a heterostructure is an effective modification strategy and has positive application value in the fields of sensors and optoelectronics. 相似文献
48.
Flammable, explosive and toxic gases, such as hydrogen, hydrogen sulfide and volatile organic compounds vapor, are major threats to the ecological environment safety and human health. Among the available technologies, gas sensing is a vital component, and has been widely studied in literature for early detection and warning. As a metal oxide semiconductor, zinc ferrite (ZnFe2O4) represents a kind of promising gas sensing material with a spinel structure, which also shows a fine gas sensing performance to reducing gases. Due to its great potentials and widespread applications, this article is intended to provide a review on the latest development in zinc ferrite based gas sensors. We first discuss the general gas sensing mechanism of ZnFe2O4 sensor. This is followed by a review of the recent progress about zinc ferrite based gas sensors from several aspects: different micro-morphology, element doping and heterostructure materials. In the end, we propose that combining ZnFe2O4 which provides unique microstructure (such as the multi-layer porous shells hollow structure), with the semiconductors such as graphene, which provide excellent physical properties. It is expected that the mentioned composites contribute to improving selectivity, long-term stability, and other sensing performance of sensors at room or low temperature. 相似文献
49.
Mengjian Hao Tiantian Yi Yongfan Cao Yinmin Song Zhenzhu Cao Weiyan He Yanfang Gao Jinrong Liu 《Advanced Powder Technology》2019,30(1):111-119
AgI/BiOCOOH composite photocatalysts have been synthesized via a simple deposition-precipitation method. The crystal structure, microstructure, element valance, light and electrical properties of as prepared samples were characterized by XRD, SEM, TEM, XPS, UV–Vis DRS, PL, EIS and photocurrent response. The loading of AgI nanoparticles endowed BiOCOOH with good visible light absorption and photocatalytic activity for degrading rhodamine B. The composition with Ag:Bi?=?1:1 exhibited the best photocatalytic activity. The enhanced photocatalytic performance could be mainly attributed to the effective separation of the photogenerated carriers at the heterojunction. O2? and h+ were suggested as the main reactive species in the photocatalytic reaction. In addition, the photocatalysts showed excellent stability over multiple reaction cycles. 相似文献
50.
《Advanced Powder Technology》2022,33(1):103354
Herein, a novel CoTiO3/BiOI (CTOB) p-n heterojunction with nanosheets-on microrods structure were prepared via a simple coprecipitation method for the first time. The catalysts were carefully characterized by various instruments. The CTOB heterostructures display improved photocatalytic performance towards RhB degradation. Among CTOB composites, CTOB-15 exhibits the optimal photocatalytic performance. Moreover, CTOB-15 also shows enhanced photocatalytic activity for MO and TC degradation compared to bare catalysts. The degradation rate constants for RhB and MO by CTOB-15 heterostructure are ca 1.6 and 1.4-fold higher than bare BiOI. The improved photocatalytic performance could be on account of the efficient separation of photoinduced carriers as well as enhanced light absorbance. Trapping experiments indicates that holes (h+) and superoxide anion radical (O2–) play a significant role in the removal of RhB by CTOB composites. The excellent photocatalytic activity and stability make it a promising photocatalyst in environmental remediation. 相似文献