Influence of thin metal base thickness on the performance of CuPc vertical organic triodes

Abstract

Articles you may be interested inMorphology and properties of a hybrid organic-inorganic system: Al nanoparticles embedded into CuPc thin film

Fully organic dye based tandem photovoltaic cells

“…The role of the intermediate gold layer should be clarified. Most likely, the back cell of the Au/PcVO/Al type is the major contributor in V oc , accounting for the Schottky contact of aluminum to phthalocyanine dye [2][3][4][5][6]8,20,21]. Besides, V oc is further increased through the impact of the ITO/PcVO/Au front cell.…”

“…Although both electrodes in the latter cell have high work functions and might formally be regarded as ohmic, the 'metal-on-dye' and 'dye-on-metal' interfaces obtained by thermal evaporation in vacuum may not be equivalent to each other [22][23][24][25][26]. Deposition of hot Au atoms on the surface of an organic dye chemically modifies the PcVO/Au interface [22][23][24] making the cell asymmetric with respect to the charge collecting electrodes [25,26], while the adjacent Au/PcVO interface formed by evaporation of dye on top of the same gold layer, indeed, provides an ohmic contact to the back cell [2,8,20,21]. Alternatively, the efficiency of such 'layer-split' cells is supposed to increase even regardless of the interface chemistry [16].…”

Influence of charge carrier injection at emitter electrode/emitter interface on the performance of metal-base organic transistors

“…For the cases of D2 and D3, a 40 nm thick PEDOT PSS film is spun cast on top of the ITO electrode at 3000 r/min for 30 s, and then annealed in vacuum at 120 o C for 2 h. Both the organic and Au films are deposited via thermal evaporation at the rate of 0.1 nms -1 under a base pressure of 10 -3 Pa. The 10 nm thick NPB film is used as the kinetic-energy enhancement layer for holes injected from the emitter, resulting in a larger barrier height of the emitter-base junction than that of the base-collector junction [11,12 ] . The evaporation rates and the film thicknesses are controlled by a quartz oscillator.…”

“…The planar architecture, generally used in the organic field-effect transistors (OFETs), has disadvantages such as low current modulation and high operation voltage due to the limitation of channel length and the low carrier mobility of the organic materials [6] . Therefore, several vertical OTFTs, including field-effect and non-fieldeffect transistors have been proposed, which have high current modulation with lower operation voltages resulting from the shorter pathways for carrier transport compared with the planer OFETs [7][8][9][10][11][12][13][14][15][16][17] .One of the most promising vertical structures is the metalbase organic transistor (MBOT), which employs an ultrathin metal layer (the base) sandwiched between two semiconductors (the emitter and the collector) [18] . In such a device, the emitter-base junction (forward-biased) and the base-collector junction (reverse-biased) are back-to-back Schottky diodes in asymmetrical configuration, i.e., the barrier height of the emitter-base junction is larger than that of the basecollector junction for the injected charge carriers from the emitter, and the two diodes are completely separated electrically by the fully covered base metal film [15,18] .…”

“…The planar architecture, generally used in the organic field-effect transistors (OFETs), has disadvantages such as low current modulation and high operation voltage due to the limitation of channel length and the low carrier mobility of the organic materials [6] . Therefore, several vertical OTFTs, including field-effect and non-fieldeffect transistors have been proposed, which have high current modulation with lower operation voltages resulting from the shorter pathways for carrier transport compared with the planer OFETs [7][8][9][10][11][12][13][14][15][16][17] .…”