Spectroscopic evidence for trap-dominated magnetic field effects in organic semiconductors

Magneto-electroluminescence effects in the single-layer organic light-emitting devices with macrocyclic aromatic hydrocarbons

“…Finally, it would be worthwhile to compare our case and the polymer-based OLED reported before. 13 Cox et al experimentally reported the long tail EL and its sign change in MEL for the polymer-based OLED, and they successfully explained their results in terms of trap-site ShockeyRead-Hall (SRH) mechanism and magnetic field effect on the spin-mixing at trap sites. 13 The similar SRH effects could also be induced by the trap enrichment with the molecular assembly and might be the physical origins of the present observations.…”

“…13 Cox et al experimentally reported the long tail EL and its sign change in MEL for the polymer-based OLED, and they successfully explained their results in terms of trap-site ShockeyRead-Hall (SRH) mechanism and magnetic field effect on the spin-mixing at trap sites. 13 The similar SRH effects could also be induced by the trap enrichment with the molecular assembly and might be the physical origins of the present observations. Detailed structure-properties relationship studies with small molecules should further deepen our understanding of MEL effects with molecular materials in the future.…”

“…The positive MEL effect at short wavelength and negative MEL effect at long wavelength in the spectrum were found. Unlike the previous work on spectrally resolved MEL, 12,13 in which devices composed of few materials, we fabricate single-layer OLEDs comprising only MAHs. The OLEDs were fabricated using the vacuum evaporation technique with metal shadow masks, which were exchanged without breaking the vacuum.…”

Non-conventional charge transport in organic semiconductors: magnetoresistance and thermoelectricity

“…10 The magnetoresistance effect is therefore amongst the largest of any nonmagnetic bulk material. OMAR immediately garnered much attention from the scientific community [6][7][8][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] because of its huge potential that could be translated into intriguing technological applications. OMAR devices do not require ferromagnetic electrodes which offers a much higher degree of freedom in the material choice not achievable for other magnetoresistive or conventional organic-based spintronic devices.…”

Analysis of trap-assisted triplet exciton quenching by magneto- conductance in rubrene-based organic light-emitting diodes

“…调控, 从而影响器件的传导电流, 这就是有机发光器 件中的磁电导(magneto-conductance, MC)效应. 此外, 由于陷阱是带隙中具有能量的局域态, 并且是无序 或结晶有机半导体中不可避免的成分, 因此常能够 束缚有机光电子器件中的电荷或激子, 但在具体研 究工作中它们的影响常被忽略 [15,16] . 若考虑器件中 陷阱的存在, T激子的淬灭作用还包括两种通道: (1) 自由的T激子与束缚的极化子相互作用(free triplettrapped polaron interaction, TP t I, T+P t →S 0 +P) [13,17~21] ;…”