真性半導体

WordNet

situated within or belonging solely to the organ or body part on which it acts; "intrinsic muscles"
belonging to a thing by its very nature; "form was treated as something intrinsic, as the very essence of the thing"- John Dewey (同)intrinsical
a substance as germanium or silicon whose electrical conductivity is intermediate between that of a metal and an insulator; its conductivity increases with temperature and in the presence of impurities (同)semiconducting material

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(価値・質などが)本質的な,本来備わった
(電気の)半導体

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/08/02 01:47:22」(JST)

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An intrinsic semiconductor, also called an undoped semiconductor or i-type semiconductor, is a pure semiconductor without any significant dopant species present. The number of charge carriers is therefore determined by the properties of the material itself instead of the amount of impurities. In intrinsic semiconductors the number of excited electrons and the number of holes are equal: n = p.

The electrical conductivity of intrinsic semiconductors can be due to crystallographic defects or electron excitation. In an intrinsic semiconductor the number of electrons in the conduction band is equal to the number of holes in the valence band. An example is Hg
0.8Cd
0.2Te at room temperature.

An indirect band gap intrinsic semiconductor is one in which the maximum energy of the valence band occurs at a different k (k-space wave vector) than the minimum energy of the conduction band. Examples include silicon and germanium. A direct band gap intrinsic semiconductor is one where the maximum energy of the valence band occurs at the same k as the minimum energy of the conduction band. Examples include gallium arsenide.

A silicon crystal is different from an insulator because at any temperature above absolute zero, there is a finite probability that an electron in the lattice will be knocked loose from its position, leaving behind an electron deficiency called a "hole". If a voltage is applied, then both the electron and the hole can contribute to a small current flow.

The conductivity of a semiconductor can be modeled in terms of the band theory of solids. The band model of a semiconductor suggests that at ordinary temperatures there is a finite possibility that electrons can reach the conduction band and contribute to electrical conduction.

The term intrinsic here distinguishes between the properties of pure "intrinsic" silicon and the dramatically different properties of doped n-type or p-type semiconductors.

Electrons and holes

In an intrinsic semiconductor such as silicon at temperatures above absolute zero, there will be some electrons which are excited across the band gap into the conduction band and which can support current flow. When the electron in pure silicon crosses the gap, it leaves behind an electron vacancy or "hole" in the regular silicon lattice. Under the influence of an external voltage, both the electron and the hole can move across the material. In an n-type semiconductor, the dopant contributes extra electrons, dramatically increasing the conductivity. In a p-type semiconductor, the dopant produces extra vacancies or holes, which likewise increase the conductivity. It is however the behavior of the p-n junction which is the key to the enormous variety of solid-state electronic devices.

Semiconductor current

The current which will flow in an intrinsic semiconductor consists of both electron and hole current. That is, the electrons which have been freed from their lattice positions into the conduction band can move through the material. In addition, other electrons can hop between lattice positions to fill the vacancies left by the freed electrons. This additional mechanism is called hole conduction because it is as if the holes are migrating across the material in the direction opposite to the free electron movement. The current flow in an intrinsic semiconductor is influenced by the density of energy states which in turn influences the electron density in the conduction band. This current is highly temperature dependent.

References

Sze, Simon M. (1981). Physics of Semiconductor Devices (2nd ed.). John Wiley and Sons (WIE). ISBN 0-471-05661-8.
Kittel, Ch. (2004). Introduction to Solid State Physics. John Wiley and Sons. ISBN 0-471-41526-X.

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English Journal

Ba3 v2 s4 o3 : a mott insulating frustrated quasi-one-dimensional s=1 magnet.

Hopkins EJ1, Prots Y, Burkhardt U, Watier Y, Hu Z, Kuo CY, Chiang JC, Pi TW, Tanaka A, Tjeng LH, Valldor M.
Chemistry (Weinheim an der Bergstrasse, Germany).Chemistry.2015 May 18;21(21):7938-43. doi: 10.1002/chem.201406511. Epub 2015 Apr 15.
Through a solid-state reaction, a practically phase pure powder of Ba3 V2 S4 O3 was obtained. The crystal structure was confirmed by X-ray single-crystal and synchrotron X-ray powder diffraction (P63 , a=10.1620(2), c=5.93212(1) Å). X-ray absorption spectroscopy, in conjunction with multiplet cal
PMID 25876532

Surface Defects on Natural MoS2.

Addou R, Colombo L, Wallace RM.
ACS applied materials & interfaces.ACS Appl Mater Interfaces.2015 May 17. [Epub ahead of print]
Transition metal dichalcogenides (TMDs) are being considered for making a variety of electronic and optoelectronic devices such as beyond complementary metal-oxide-semiconductor (CMOS) switches, light-emitting diodes, solar cells, as well as sensors among others. Molybdenum disulfide (MoS2) is the m
PMID 25980312

Reduced graphene oxide-ZnO self-assembled films: tailoring the visible light photoconductivity by the intrinsic defect states in ZnO.

Kavitha MK1, Gopinath P, John H.
Physical chemistry chemical physics : PCCP.Phys Chem Chem Phys.2015 May 14. [Epub ahead of print]
ZnO is a wide direct bandgap semiconductor; its absorption can be tuned to the visible spectral region by controlling the intrinsic defect levels. Combining graphene with ZnO can improve its performance by photo-induced charge separation by ZnO and electronic transport through graphene. When reduced
PMID 25971240

Japanese Journal

Impact of Junction Nonabruptness on Random-Discrete-Dopant Induced Variability in Intrinsic Channel Trigate Metal--Oxide--Semiconductor Field-Effect Transistors

Wei Kang Liang,Liu Xiao Yan,Du Gang
Jpn J Appl Phys 52(4), 04CC09-04CC09-4, 2013-04-25
… Using full three-dimensional (3D) technology computer-aided design (TCAD) simulations, we present a comprehensive statistical study on the random discrete dopant (RDD) induced variability in state-of-the-art intrinsic channel trigate MOSFETs. …
NAID 40019637877

Direct Measurement of Carrier Mobility in Intrinsic Channel Tri-Gate Single Silicon Nanowire Metal--Oxide--Semiconductor Field-Effect Transistors

Mao Ke,Saraya Takuya,Hiramoto Toshiro
Jpn J Appl Phys 52(4), 04CC08-04CC08-6, 2013-04-25
… In this paper, we report the direct measurement of intrinsic carrier mobility in ``single-silicon-nanowire metal--oxide--semiconductor field-effect transistors (MOSFETs) for the first time. … To obtain intrinsic carrier mobility with high accuracy by the split capacitance--voltage (C--V) method, ultralong single-silicon-nanowires, instead of multiple parallel nanowires, were designed and fabricated. …
NAID 40019637868

Optimization of Dislocation Edge Stress Effects for Si N-Type Metal--Oxide--Semiconductor Field-Effect Transistors

Liao Ming-Han,Chen Ci-Hua,Chang Li-Chen,Yang Chen,Yu Ming-Yuan,Liu Gan-Han,Kao Si-Cha
Jpn J Appl Phys 52(4), 04CC20-04CC20-4, 2013-04-25
… The comprehensive investigation on the effect of dislocation edge stress for Si N-type metal--oxide--semiconductor field-effect transistors (N-MOSFETs) is presented in this work by the experimental measurement and proposed simulation model. …
NAID 150000106683