Patterned growth of pentacene

Abstract

We propose a way of patterning organic small molecule thin films without requiring a hardmask and therefore more compatible with printing technologies. Active and passive areas for transistors are predefined by different surface chemistries. The subsequent growth takes place under conditions that cause the formation of a high mobility two-dimensional film in the active area and a disconnected three-dimensional film or no film in the passive area. This concept is founded on the basic theory of nucleation of organic small molecules on inert substrates and applied to the growth of patterned pentacene layers.

Controlled Deposition of Crystalline Organic Semiconductors for Field‐Effect‐Transistor Applications

“…When thick and rough OTS films are printed onto a smooth OTS monolayer, the selective nucleation of crystals is preserved, indicating that this patterning technique differs from previously reported techniques for patterning pentacene thin films, which rely on a contrast in surface chemistry. [68,69] The rough topography in the stamped OTS domains was concluded to be the predominant factor in the selective nucleation. Inspections of the underside of patterned crystals using atomic force microscopy (AFM) and optical microscopy further revealed that crystal nucleation occurs at the base of the rough OTS surface, and the crystal then grows either conformally to the OTS pillars, or by initially growing around or away from the rough pillars, then pushing the pillars away.…”

BODIPY derivatives as n-type organic semiconductors: Isomer effect on carrier mobility

“…The development of single-crystal organic field effect transistors (SCOFETs) makes it possible to explore intrinsic properties of these materials [9][10][11]. p-Type organic semiconductors such as pentacene, rubrene and derivatives of them have been investigated widely [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. The recently improved theoretical understandings of organic semiconductors have even addressed the design rule of organics with high hole mobilities [28][29][30][31].…”

Organic semiconductors for device applications: current trends and future prospects

“…In further extended studies [354], it was noted that the stamped OTS films were particularly not as smooth as a self-assembled OTS monolayers, as the stamped domains were populated with large numbers of approx. 100-nm-tall OTS pillars that facilitated the selective nucleation [356,357]. This, in fact, was further clarified by observing that nucleation started from the base of the rough OTS surface and the crystal grew on the surface of OTS pillars [354].…”

“…Although SAMs of functionalized thiols supported on metal films were successful in promoting nucleation and growth of inorganic crystals with finely tuned crystal sizes, crystallographic orientation, and crystal micropatterning [362,[597][598][599], their uses in organic crystallization were rather limited due to prevailing van der Waals interactions against the ionic ones that were critical at the organic-inorganic interfaces. It was found that patterned SAM templates could produce site-specific crystallization of organic charge transferring salts [600] and pentacene films [356,357]. Successful growth of 100 μm size pentacene single crystals was induced by Si surface modified with a monolayer of cyclohexene molecules [451].…”

“…Site-selective pentacene thin-film growth on OTS-treated Au surface was attributed to different types of surface interactions [356]. For instance, selective pentacene growth on SiO 2 -coated substrate with OTS and perfluorodecyltrichlorosilane (FDTS) stamps resulted [357] only within a small window of growth conditions. However, the selectivity of the above-referred growth was due more to the roughness of the thick OTS-stamped film.…”