Improvement of photoelectrochemical properties of chloroaluminum phthalocyanine thin films by controlled crystallization and molecular orientation

Yanagi, Hisao; Douko, Shinya; Ueda, Y.; Ashida, Michio; Woehrle, D.

doi:10.1021/j100182a064

Cited by 74 publications

(23 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the obtained spectrum S and the reference spectrum R taken before the film deposition, the absorbance spectrum A was calculated using the following equation: A ¼ -log 10 (S/R). The energy gap of (1.52 AE 0.01) eV was obtained from the threshold of Q-band, which agrees with literature reports (1.4-1.5 eV) [16,29].…”

supporting

confidence: 91%

See 1 more Smart Citation

Origin of Carrier Types in Intrinsic Organic Semiconductors

Kaji¹,

Entani²,

Ikeda³

et al. 2008

Advanced Materials

View full text Add to dashboard Cite

What determines carrier types in organic semiconductors? This question is growing in the recent studies of organic field-effect transistors (FETs), because ambipolar operation has been effected in FETs of several organic semiconductors. [1][2][3][4][5][6][7] This means that the carrier type -electron or holecould be controlled by the external voltage although each organic semiconductor is considered to have either p-or n-character in normal conduction. The origin of such a native carrier type is, in most cases, empirically explained by the energy positions of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) relative to the work function of the electrode metal. This answer is, however, too naïve and not quantitative, judging from the recent surface-science results [8][9][10][11][12][13][14] that point out the absence of universal rule for the energy alignment at the metal-organic semiconductor interfaces. In this study, we succeeded in changing the carrier injection barriers and observing the resultant change of carrier type in an organic FET. The key factor is the usage of an identical specimen for both electrical and electronic measurements. The field-effect mobilities, evaluated from conventional three-terminal measurements, decreased exponentially with precisely evaluated charge injection barrier, independent of carrier type; this suggests that the carrier type of intrinsic organic semiconductors is not determined a priori but is governed by the formation of an interface with a metal electrode.

show abstract

supporting

confidence: 91%

“…AlPcCl was regarded as a p-type semiconductor in many reports, [16] but n-type nature has also been reported. [17] Thus, this material is the most appropriate for discussing the decisive factor of the carrier type in relation to various physical properties.…”

mentioning

confidence: 99%

Origin of Carrier Types in Intrinsic Organic Semiconductors

Kaji¹,

Entani²,

Ikeda³

et al. 2008

Advanced Materials

View full text Add to dashboard Cite

show abstract

“…In the present experiments, we cannot control the organization of organic molecules in a molecular level, for example, the complete control of molecular alignment of [tM(pc)] in thin films [34]. If this control can be achieved to the degree that the thin film can be used as a solid device, the performance will be more dramatically improved.…”

Section: Electroluminescent Device Using [Cu(pc)]-[zn(pc)] Double-laymentioning

confidence: 88%

Construction of a ‘Sequential Potential Field’ by [Cu(pc)]/[Zn(pc)] double-layered Thin Film: Application to Electrochromic and Electroluminescent Devices

Tominaga

Hayashi

Toshima

1997

J. Porphyrins Phthalocyanines

View full text Add to dashboard Cite

‘Sequential potential field’ is a concept to produce a potential cascade by the organization of redox components, and to aim for an effective and vectorial electron and/or hole transfer. Construction of the sequential potential field is examined by double-layered thin film composed of two kinds of metallophthalocyanine having different oxidation potentials, i.e. copper phthalocyanine and zinc phthalocyanine. In the electrochromic device of double-layered metallophthalocyanine thin films, hole transfer can be controlled by the order of deposition, which suggests that the present system is suitable for the construction of a sequential potential field. Double-layered metallophthalocyanine thin films were also used as a hole transfer layer in all-solid organic electroluminescent devices. In the case of an indium-tin oxide/copper phthalocyanine/zinc phthalocyanine/tris(8-hydroxyquinoline)aluminum/ Mg - Ag device for electroluminescence, a high brightness of more than 4000 cd m−2 can be achieved. This double-layered hole transfer system is more effective than the corresponding single hole transfer system, which is due to the construction of a sequential potential field in the hole transfer layer.

show abstract

“…The role of oxygen as a dopant leading to the typically observed p -type characteristics of phthalocyanines could be clearly elucidated in these studies [197,202,203] . An optimized orientation of crystals led to larger exciton diffusion lengths and charge carrier mobilities as shown in an increased photoelectrochemical effi ciency [204] . A detailed analytical investigation of different ways of chemical treatment of PcAl(Cl) as compared to PcGa(Cl) and PcIn(Cl) revealed the hydrolysis of the Al -Cl bond as the key step towards the formation of more effi cient electrode materials [196] .…”

Section: Photoelectrochemistry At Phthalocyanine Thin Filmsmentioning

confidence: 99%