Growth behavior of CuPc films by physical vapor deposition

Abstract

Various Cu-phthalocyanine (CuPc) films were grown from physical vapor deposition on top of indium-tinoxide glass substrates by controlling substrate temperature (T sub ), source temperature (T sou ), and growth time. From side-view SEM pictures, the growth rates for these CuPc films are estimated and can be categorized into three regions. From the Arrhenius plot of growth rate versus 1/T sub , the activation energy E A can be obtained. As T sou = 390 °C, for region (A) with T sub < 140 °C, the growth of CuPc films is dominated by the adhesion process with E A = 810 meV. For region (B) with 140 °C < T sub < 320 °C, the growth is then limited by the steric character associated with the organic molecular solids with E A = 740 meV. For region (C) with T sub > 320 °C, the re-evaporation of the CuPc adhered molecules from the interface becomes dominant.

Copper phthalocyanine thin films on Cu(111): Sub-monolayer to multi-layer

“…In the solid phase, CuPc forms a number of organic molecular crystal polymorphs including the thermodynamically stable β-phase and at least eight additional metastable phases [5]. When grown from vapor deposition in vacuum, CuPc generally forms the meta-stable α-phase at room temperature and the β-phase at temperatures exceeding 210°C (the α-phase can be converted to the β-phase by heating above 210°C) [6,7]. Of the many polymorphs, the α-and β-phases are the most widely studied, and see the widest industrial use.…”

Re-condensation and decomposition of Tris(8-hydroxyquinoline)-aluminum in a vapor transport ampoule

“…Thus, the T sub -dependence of the physical properties of the Alq 3 films deposited at T sub ffi 90-120 1C [14] was not due to the isomeric transformation but could be attributed to the steric effect that the higher thermal energy (for T sub Z120 1C) allowing an adjustment of correct orientation among these complex Alq 3 molecules to form a crystalline phase leads to a change in the activation energy for the adhesion process [16,23,24]. Similar behavior about this steric effect was also observed during the deposition of small organic molecular films of C 60 [22] and Cu-phthalocyanine [23].…”

“…4, with the as-received Alq 3 source powder and ambient air inside the ampoule of p in ¼ 1.3 Â 10 2 Pa, two tube-wall deposition zones due to CSS were observed. Inside a CSS zone, the molecular solid phase nucleates and grows on the tube-wall because the local actual vapor pressure of this molecular species (originated from high T source ) exceeds its equilibrium vapor pressure (related to local sidewall temperature T side ) [19][20][21][22][23][24]. The lower CSS zone was formed by a yellow color thick film around the tube wall with T side ffi 130-270 1C, while the upper one was formed by several transparent needle crystals with T side ffi RT.…”

“…Here, from a constitutional supersaturation (CSS) study inside a vapor transport ampoule [19][20][21][22][23][24], the re-condensation and decomposition of Alq 3 together with the formation of 8-hydroxyquinoline (8Hq, C 9 H 6 NOH [25][26][27][28]) crystals are investigated with respect to various transport gases under different inside pressures (p in ). The physical properties of the as-deposited Alq 3 and 8Hq samples were characterized by x-ray diffraction (XRD), UV-visible (UVvis) and Fourier transform infrared (FTIR) spectroscopies, and discussed with respect to various fabrication parameters.…”

Progress in Modification of Indium-Tin Oxide/Organic Interfaces for Organic Light-Emitting Diodes

“…For T sub > 320 • C, the re-evaporation of the CuPc adhered molecules from the interface become dominant. 208 It has been shown that a CuPc layer inserted between the ITO and the HTL of an OLED structure produces a significant improvement in device performance, particularly device lifetime by reducing the ITO-induced degradation on the HTL. 185 The role of CuPc layer for the injection of holes from ITO anode into HTL has also been detected.…”