The Discovery of a Superhard P-type Transparent Semiconductor: Al2.69B50

2021 ◽  
Author(s):  
Xu Zheng ◽  
Dayu Yan ◽  
Changjiang Yi ◽  
Jinlong Zhu ◽  
Qinghua Zhang ◽  
...  

Superhard semiconductors have been long sought after for electronic device applications enduring extreme conditions, such as astronautics, due to their intrinsic toughness, high thermal and chemical stability. Here, we report...

1998 ◽  
Vol 537 ◽  
Author(s):  
M.A.L. Johnson ◽  
Zhonghai Yu ◽  
J.D. Brown ◽  
F.A. Koeck ◽  
N.A. El-Masry ◽  
...  

AbstractA systematic study of the growth and doping of GaN, AlGaN, and InGaN by both molecular beam epitaxy (MBE) and metal-organic vapor phase epitaxy (MOVPE) has been performed. Critical differences between the resulting epitaxy are observed in the p-type doping using magnesium as the acceptor species. MBE growth, using rf-plasma sources to generate the active nitrogen species for growth, has been used for III-Nitride compounds doped either n-type with silicon or p-type with magnesium. Blue and violet light emitting diode (LED) test structures were fabricated. These vertical devices required a relatively high forward current and exhibited high leakage currents. This behavior was attributed to parallel shorting mechanisms along the dislocations in MBE grown layers. For comparison, similar devices were fabricated using a single wafer vertical flow MOVPE reactor and ammonia as the active nitrogen species. MOVPE grown blue LEDs exhibited excellent forward device characteristics and a high reverse breakdown voltage. We feel that the excess hydrogen, which is present on the GaN surface due to the dissociation of ammonia in MOVPE, acts to passivate the dislocations and eliminate parallel shorting for vertical device structures. These findings support the widespread acceptance of MOVPE, rather than MBE, as the epitaxial growth technique of choice for III-V nitride materials used in vertical transport bipolar devices for optoelectronic applications.


Author(s):  
Kohei Yamasue ◽  
Yasuo Cho

Abstract Two-dimensional semiconductors such as atomically-thin MoS2 have recently gained much attention because of their superior material properties fascinating for the future electronic device applications. Here we investigate the nanoscale dominant carrier distribution on atomically-thin natural and Nbdoped MoS2 mechanically exfoliated on SiO2/Si substrates by using scanning nonlinear dielectric microscopy. We show that a few-layer natural MoS2 sample is an n-type semiconductor, as expected, but Nb-doped MoS2, normally considered as a p-type semiconductor, can unexpectedly become an n-type semiconductor due to strong unintentional electron doping.


1999 ◽  
Vol 4 (S1) ◽  
pp. 594-599 ◽  
Author(s):  
M.A.L. Johnson ◽  
Zhonghai Yu ◽  
J.D. Brown ◽  
F.A. Koeck ◽  
N.A. El-Masry ◽  
...  

A systematic study of the growth and doping of GaN, AlGaN, and InGaN by both molecular beam epitaxy (MBE) and metal-organic vapor phase epitaxy (MOVPE) has been performed. Critical differences between the resulting epitaxy are observed in the p-type doping using magnesium as the acceptor species. MBE growth, using rf-plasma sources to generate the active nitrogen species for growth, has been used for III-Nitride compounds doped either n-type with silicon or p-type with magnesium. Blue and violet light emitting diode (LED) test structures were fabricated. These vertical devices required a relatively high forward current and exhibited high leakage currents. This behavior was attributed to parallel shorting mechanisms along the dislocations in MBE grown layers. For comparison, similar devices were fabricated using a single wafer vertical flow MOVPE reactor and ammonia as the active nitrogen species. MOVPE grown blue LEDs exhibited excellent forward device characteristics and a high reverse breakdown voltage. We feel that the excess hydrogen, which is present on the GaN surface due to the dissociation of ammonia in MOVPE, acts to passivate the dislocations and eliminate parallel shorting for vertical device structures. These findings support the widespread acceptance of MOVPE, rather than MBE, as the epitaxial growth technique of choice for III-V nitride materials used in vertical transport bipolar devices for optoelectronic applications.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Matthew J. Gilbert

AbstractWithin the broad and deep field of topological materials, there are an ever-increasing number of materials that harbor topological phases. While condensed matter physics continues to probe the exotic physical properties resulting from the existence of topological phases in new materials, there exists a suite of “well-known” topological materials in which the physical properties are well-characterized, such as Bi2Se3 and Bi2Te3. In this context, it is then appropriate to ask if the unique properties of well-explored topological materials may have a role to play in applications that form the basis of a new paradigm in information processing devices and architectures. To accomplish such a transition from physical novelty to application based material, the potential of topological materials must be disseminated beyond the reach of condensed matter to engender interest in diverse areas such as: electrical engineering, materials science, and applied physics. Accordingly, in this review, we assess the state of current electronic device applications and contemplate the future prospects of topological materials from an applied perspective. More specifically, we will review the application of topological materials to the general areas of electronic and magnetic device technologies with the goal of elucidating the potential utility of well-characterized topological materials in future information processing applications.


2007 ◽  
Vol 556-557 ◽  
pp. 153-156
Author(s):  
Chi Kwon Park ◽  
Gi Sub Lee ◽  
Ju Young Lee ◽  
Myung Ok Kyun ◽  
Won Jae Lee ◽  
...  

A sublimation epitaxial method, referred to as the Closed Space Technique (CST) was adopted to produce thick SiC epitaxial layers for power device applications. In this study, we aimed to systematically investigate surface morphologies and electrical properties of SiC epitaxial layers grown with varying a SiC/Al ratio in a SiC source powder during the sublimation growth using the CST method. It was confirmed that the acceptor concentration of epitaxial layer was continuously decreased with increasing the SiC/Al ratio. The blue light emission was successfully observed on a PN diode structure fabricated with the p-type SiC epitaxial layer. Furthermore, 4H-SiC MESFETs having a micron-gate length were fabricated using a lithography process and their current-voltage performances were characterized.


Author(s):  
TaeGyeong Lim ◽  
Ba Trung Ho ◽  
Ji Won Suk

Highly porous activated graphene coated on CVD-graphene/Cu wires enables high-performance wire supercapacitors with enhanced thermal and chemical stability.


2021 ◽  
Author(s):  
Taksande Kiran ◽  
Effrosyni Gkaniatsou ◽  
Corine Simonnet-Jégat ◽  
Carine Livage ◽  
Guillaume Maurin ◽  
...  

A highly performing proton conducting composite was prepared through the impregnation of EMIMCl ionic liquid in the mesoporous MIL-101(Cr)-SO3H MOF. The resulting EMIMCl@MIL-101(Cr)-SO3H composite displays high thermal and chemical stability,...


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