Direct growth of high quality graphene nanowalls on dielectric surfaces by plasma-enhanced chemical vapor deposition for photo detection

Abstract

A method for direct growth of graphene nanowalls (GNWs) on an insulating substrate by plasma enhanced chemical vapor deposition (PECVD) is reported. The effects of growth temperature, plasma power, carbon source concentration, gas ratio and growth time on the quality of GNWs are systematically studied. The Raman spectrum shows that the obtained GNWs have a relatively high quality with a D to G peak ratio (ID/IG) of 0.42. Based on the optimization of the quality of GNWs, a field-effect transistor (FET) photodetector is prepared for the first time, and its photo-response mechanism is analyzed. The responsivity of the photodetector is 160 mA/W at 792 nm and 55 mA/W at 1550 nm. The results reveal that the GNWs are promising for high performance photodetectors.

Direct Growth of Graphene Nanowalls on Silicon Using Plasma-Enhanced Atomic Layer Deposition for High-Performance Si-Based Infrared Photodetectors

“…The GNWs on Si grown by PECVD are used in many fields, such as transistor, sensors, , solar cells, − and photodetectors (PDs). − For PD applications, graphene–Si heterostructures have attracted much attention especially in the IR detection . Compared with the transferred planar graphene, the three-dimensional (3D) structured graphene materials have better light absorption ability . In addition, due to the high reflectivity of polished silicon especially in the IR range above 1200 nm, most of the IR incident light could be reflected back, whereas the employment of GNWs can improve the IR light absorption.…”

“…Similarly, Liu et al demonstrated a GNW-based IR PD and the performance of the device was improved by interface modification by Au . However, the performances of such graphene–Si devices strongly depend on the quality of graphene materials. , It is known that grown GNWs suffer from defects and byproducts including amorphous carbon. , Thus, etching of amorphous carbon during the growth process can improve the quality of graphene materials. In this study, we for the first time report a PEALD method to directly grow large-area GNWs on the Si substrate and high-performance IR PDs based on the GNWs/Si heterostructure.…”

“…45 Compared with the transferred planar graphene, the three-dimensional (3D) structured graphene materials have better light absorption ability. 46 In addition, due to the high reflectivity of polished silicon especially in the IR range above 1200 nm, most of the IR incident light could be reflected back, whereas the employment of GNWs can improve the IR light absorption. Recently, various graphene−Si PDs have been reported and their performances could be improved by light management engineering and interface engineering.…”

“…44 However, the performances of such graphene−Si devices strongly depend on the quality of graphene materials. 41,46 It is known that grown GNWs suffer from defects and byproducts including amorphous carbon. 20,27 Thus, etching of amorphous carbon during the growth process can improve the quality of graphene materials.…”

Direct fabrication and characterization of vertically stacked Graphene/h-BN/Graphene tunnel junctions

“…In particular, this work focuses on the situations when the two graphene sheets have unequal doping, e.g., one is n-type (electron doped) in a single tunnel junction device and the other is p-type (hole doped). In this study, graphene and h-BN were directly deposited by radio frequency-plasma enhanced chemical vapor deposition (RF-PECVD) [76]. In the case of graphene, methane (CH 4 ) gas was used whilst ammonia borane was used for h-BN synthesis [77].…”