This study is led by Prof. Zhongfan Liu (Center for Nanochemistry, College of Chemistry and Molecular Engineering, Peking University), Prof. Jingyu Sun (College of Energy, Soochow Institute for Energy and Materials InnovationS, Soochow University) and Prof. Wanlin Guo (State Key Laboratory of Mechanics and Control of Mechanical Structures, Institute of Nanoscience, Nanjing University of Aeronautics and Astronautics). They reported an effective approach that utilizes a metal-containing species, copper acetate, to continuously supply copper clusters in a gaseous form to aid transfer-free growth of graphene on wafer-scale insulators. As-grown graphene films readily showed reduced multilayer density, improved electrical performance, and advanced carrier mobility value. Furthermore, droplet-based hydrovoltaic electricity generator devices based on directly grown graphene were found to exhibit robust voltage output and long cyclic stability, demonstrating its potential for emerging energy harvesting applications.
Direct synthesis of high-quality graphene on dielectric substrates without a transfer process is of paramount importance to aim at a variety of applications. However, directly grown graphene films tend to suffer from low crystal quality, abundant structural defects, and concurrent formation of multilayers, resulting in poor electrical/optical properties, which impede high-end applications. Current strategies for boosting high-quality graphene growth, such as remote metal catalyzation otherwise are limited by poor performance with respect to the release of metal catalysts and hence suffer from the problem of metal residues.
Herein, they reported an effective approach that utilizes a metal-containing species, copper acetate, to continuously supply copper clusters in a gaseous form to aid transfer-free growth of graphene over a wafer scale. Cu(OAc)2 was subjected to volatilization using an independent heating system to enable the delivery of Cu clusters. The derived Cu clusters enable effective decomposition of the CH4 precursor by reducing its activation energy, as exemplified by density functional theory calculations. The graphene films exhibited a carrier mobility of 8500 cm2 V−1 s−1.
As a proof-of-concept, they demonstrated the fabrication of a hydrovoltaic electricity generator device using thus-grown graphene. As-constructed generator showed superior voltage output and cyclic stability compared to its transfer-involving graphene counterparts, holding promise for practical applications. The work presented here offers a promising solution to organize the metal catalytic booster toward the transfer-free synthesis of high-quality graphene and enable smart energy generation.
See the article:
Copper acetate-facilitated transfer-free growth of high-quality graphene for hydrovoltaic generators
National Science Review