Morphology Control of Nanocrystallized C60 Thin Films Prepared by Poor Solvent Immersion

Kazuki Umemoto,Akito Masuhara,Bozhang Lyu,Miho Doi,Masaki Takeda,Yuki Tezuka

doi:10.3390/technologies6020051

Abstract

Nanocrystallized C60 thin films of such as hexagonal, plate-like, and rod-like morphologies were recrystallized by poor solvent immersion, employing 1-propanol, 2-propanol, and butanol respectively. A C60 thin film fabricated by evaporation was immersed in the poor solvent, partially dissolving the surface C60. This was followed by the solvent rapidly reaching a supersaturated state, resulting in the induced recrystallization of the C60. C60 fine high-density crystals were successfully prepared using propanol, with crystal sizes varying between 84 and 141 nm by changing the immersion time. In addition, due to the 1-propanol recrystallizing solvated crystals which were formed through interactions between the solvent and the C60, uniform C60 fine crystals were obtained by the formation of a large number of nucleation sites.

Highlights

Organic semiconductor materials in the form of fullerenes have been intensively studied as attractive materials for various state-of-art devices such as field effect transistors [1], light emitting diodes [2], chemical sensors [3], photodetectors [4], and solar cells [5]
We propose the poor solvent immersion to control the morphologies of nanocrystallized C60 thin films using as-deposited C60 thin film
A thermally evaporated C60 thin film is immersed in a poor solvent and the surface morphologies are controlled by the recrystallization of C60

Summary

Introduction

Organic semiconductor materials in the form of fullerenes have been intensively studied as attractive materials for various state-of-art devices such as field effect transistors [1], light emitting diodes [2], chemical sensors [3], photodetectors [4], and solar cells [5]. In several kinds of fullerenes, C60 shows promising optoelectronic properties [6,7,8] that are expected to be developed further. In terms of the applications of C60 for various optoelectronic devices, morphology control of C60 fine crystals in thin film state enables control of nanostructures, which can improve device performances. Approaches of morphology control through use of solutions are required for various optoelectronic devices that necessitate cost-effective process and higher device performance [12]. Several techniques have been developed to control the morphologies of C60 fine crystals without the demanding requirements of using templates, special equipment, high temperature, or high pressure

Methods

Results

Conclusion