“Photoconductivity”的意思、由来-开放百科全书

When light is absorbed by a material such as a semiconductor, the number of free electrons and electron holes increases and raises its electrical conductivity.^[2] To cause excitation, the light that strikes the semiconductor must have enough energy to raise electrons across the band gap, or to excite the impurities within the band gap. When a bias voltage and a load resistor are used in series with the semiconductor, a voltage drop across the load resistors can be measured when the change in electrical conductivity of the material varies the current through the circuit.

Applications

When a photoconductive material is connected as part of a circuit, it functions as a resistor whose resistance depends on the light intensity. In this context, the material is called a photoresistor (also called light-dependent resistor or photoconductor). The most common application of photoresistors is as photodetectors, i.e. devices that measure light intensity. Photoresistors are not the only type of photodetector—other types include charge-coupled devices (CCDs), photodiodes and phototransistors—but they are among the most common. Some photodetector applications in which photoresistors are often used include camera light meters, street lights, clock radios, infrared detectors, nanophotonic systems and low-dimensional photo-sensors devices.^[4]

Negative photoconductivity

Some materials exhibit deterioration in photoconductivity upon exposure to illumination.^[5] One prominent example is hydrogenated amorphous silicon (a-Si:H) in which a metastable reduction in photoconductivity is observable^[6] (see Staebler–Wronski effect). Other materials that were reported to exhibit negative photoconductivity include molybdenum disulfide,^[7] graphene,^[8] indium arsenide nanowires,^[9] and metal nanoparticles.^[10]

Magnetic photoconductivity

In 2016 it was demonstrated that in some photoconductive material a magnetic order can exist.^[11] One prominent example is CH₃NH₃(Mn:Pb)I₃. In this material a light induced magnetization melting was also demonstrated^[11] thus could be used in magneto optical devices and data storage.

See also

References

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2. ^{{cite journal|last1=Saghaei|first1=Jaber|last2=Fallahzadeh|first2=Ali|last3=Saghaei|first3=Tayebeh|title=Vapor treatment as a new method for photocurrent enhancement of UV photodetectors based on ZnO nanorods|journal=Sensors and Actuators A: Physical|date=June 2016|volume=247|pages=150–155|doi=10.1016/j.sna.2016.05.050|url=http://www.sciencedirect.com/science/article/pii/S0924424716302849}}
3. ^{{cite journal |doi=10.1021/cr00017a020 |first=Kock Yee |last=Law |title=Organic photoconductive materials: recent trends and developments |journal=Chemical Reviews, American Chemical Society |volume=93 |pages=449–486 |year=1993}}
4. ^{{cite journal |last1=Hernández-Acosta |first1=M A |last2=Trejo-Valdez |first2=M |last3=Castro-Chacón |first3=J H |last4=Torres-San Miguel |first4=C R |last5=Martínez-Gutiérrez |first5=H |last6=Torres-Torres |first6=C |title=Chaotic signatures of photoconductive Cu ZnSnS nanostructures explored by Lorenz attractors |journal=New Journal of Physics |date=23 February 2018 |volume=20 |issue=2 |pages=023048 |doi=10.1088/1367-2630/aaad41}}
5. ^{{cite book|author=N V Joshi|title=Photoconductivity: Art: Science & Technology|url=https://books.google.com/books?id=lv-Nb5-H3pQC&pg=PA272|date=25 May 1990|publisher=CRC Press|isbn=978-0-8247-8321-1}}
6. ^{{cite journal|last1=Staebler|first1=D. L.|last2=Wronski|first2=C. R.|title=Reversible conductivity changes in discharge-produced amorphous Si|journal=Applied Physics Letters|volume=31|issue=4|year=1977|pages=292|issn=0003-6951|doi=10.1063/1.89674|bibcode = 1977ApPhL..31..292S }}
7. ^{{cite journal|last1=Serpi|first1=A.|title=Negative Photoconductivity in MoS2|journal=Physica Status Solidi A|volume=133|issue=2|year=1992|pages=K73–K77|issn=0031-8965|doi=10.1002/pssa.2211330248|bibcode = 1992PSSAR.133...73S }}
8. ^{{cite journal|last1=Heyman|first1=J. N.|last2=Stein|first2=J. D.|last3=Kaminski|first3=Z. S.|last4=Banman|first4=A. R.|last5=Massari|first5=A. M.|last6=Robinson|first6=J. T.|title=Carrier heating and negative photoconductivity in graphene|journal=Journal of Applied Physics|volume=117|issue=1|year=2015|pages=015101|issn=0021-8979|doi=10.1063/1.4905192|arxiv = 1410.7495 |bibcode = 2015JAP...117a5101H }}
9. ^{{Cite journal|last=Alexander-Webber|first=Jack A.|last2=Groschner|first2=Catherine K.|last3=Sagade|first3=Abhay A.|last4=Tainter|first4=Gregory|last5=Gonzalez-Zalba|first5=M. Fernando|last6=Di Pietro|first6=Riccardo|last7=Wong-Leung|first7=Jennifer|last8=Tan|first8=H. Hoe|last9=Jagadish|first9=Chennupati|date=2017-12-11|title=Engineering the Photoresponse of InAs Nanowires|journal=ACS Applied Materials & Interfaces|language=EN|volume=9|issue=50|pages=43993–44000|doi=10.1021/acsami.7b14415|pmid=29171260|issn=1944-8244}}
10. ^{{cite journal|last1=Nakanishi|first1=Hideyuki|last2=Bishop|first2=Kyle J. M.|last3=Kowalczyk|first3=Bartlomiej|last4=Nitzan|first4=Abraham|last5=Weiss|first5=Emily A.|last6=Tretiakov|first6=Konstantin V.|last7=Apodaca|first7=Mario M.|last8=Klajn|first8=Rafal|last9=Stoddart|first9=J. Fraser|last10=Grzybowski|first10=Bartosz A.|title=Photoconductance and inverse photoconductance in films of functionalized metal nanoparticles|journal=Nature|volume=460|issue=7253|year=2009|pages=371–375|issn=0028-0836|doi=10.1038/nature08131|bibcode = 2009Natur.460..371N|pmid=19606145}}
11. ^¹{{cite journal|last1=Náfrádi|first1=Bálint|title=Optically switched magnetism in photovoltaic perovskite CH3NH3(Mn:Pb)I3|journal=Nature Communications|date=24 November 2016|volume=7|issue=13406|page=13406|doi=10.1038/ncomms13406|pmid=27882917|pmc=5123013|url=http://www.nature.com/articles/ncomms13406|arxiv=1611.08205|bibcode=2016NatCo...713406N}}