Lithuanian Journal of Physics article / Lietuvos fizikos žurnalo straipsnis

CHARGE CARRIER TRANSPORT AND RECOMBINATION IN DISORDERED MATERIALS
Gytis Juška, Kęstutis Arlauskas, and Kristijonas Genevičius
Department of Solid State Electronics, Vilnius University, Saulėtekio 3A, LT-10222 Vilnius, Lithuania
E-mail: kestutis.arlauskas@ff.vu.lt

Received 8 July 2016; accepted 23 September 2016

In this brief review the methods for investigation of charge carrier transport and recombination in thin layers of disordered materials and the obtained results are discussed. The method of charge carrier extraction by linearly increasing voltage (CELIV) is useful for the determination of mobility, bulk conductivity and density of equilibrium charge carriers. The extraction of photogenerated charge carriers (photo-CELIV) allows one to independently investigate relaxation of both the mobility and density of photogenerated charge carriers. The extraction of injected charge carriers (i-CELIV) is effective for the independent investigation of transport peculiarities of both injected holes and electrons in bulk heterojunctions. For the investigation of charge carrier recombination we proposed integral time-of-flight (TOF) and double-injection (DI) current transient methods. The methods allowed us to obtain the following significant results: to determine the reason of the conductivity dependence on electric field strength and temperature in the amorphous and microcrystalline hydrogenated silicon and π-conjugated polymers, the time dependent Langevin recombination, the impact of morphology on charge carrier mobility, the reason of reduced Langevin recombination in RR-PHT (regioregular poly(3-hexylthiophene))/PCBM (1-(3-methoxycarbonyl)propyl-1phenyl-[6,6]-methanofullerene) bulk heterojunction structures – 2D Langevin recombination; and to evaluate that the mobility of holes is predetermined by off-diagonal dispersion in poly-PbO.

Keywords: disordered materials, mobility, recombination
PACS: 72.20Jv, 72.80Le, 73.50Jt, 88.40jr

KRŪVININKŲ PERNAŠA IR REKOMBINACIJA NETVARKIOSIOSE MEDŽIAGOSE

Gytis Juška, Kęstutis Arlauskas, Kristijonas Genevičius
Vilniaus universiteto Kietojo kūno elektronikos katedra, Vilnius, Lietuva

Šioje apžvalgoje pateikti krūvininkų pernašos ir rekombinacijos netvarkiosiose medžiagose tyrimo metodai ir gauti rezultatai. Pusiausvyrinių krūvininkų ekstrakcijos tiesiškai didėjančia įtampa metodas (CELIV) patogus matuojant krūvininkų judrį, tankį ir tūrinį laidumą. Fotogeneruotų krūvininkų ekstrakcijos metodas (photo-CELIV) įgalina atskirai matuoti krūvininkų judrio ir tankio relaksaciją po fotosužadinimo. Injektuotų krūvininkų ekstrakcijos metodas (i-CELIV) patogus nustatant elektronų ir skylių judrius tūrinėse heterosandūrose atskirai. Krūvininkų rekombinacijai tirti taip pat pasiūlyti integrinis lėkio trukmės ir dvigubos injekcijos srovės kinetikos metodai. Tiriant amorfinio ir mikrokristalinio silicio, švino oksido ir π-konjuguotų polimerų bei jų tūrinių heterosandūrų elektrines savybes šiais metodais, gauti svarbūs rezultatai.

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