Opening the band gap of graphene through silicon doping for the improved performance of graphene/GaAs heterojunction solar cells

Abstract

Graphene has attracted increasing interest due to its remarkable properties. However, the zero band gap of monolayered graphene limits it's further electronic and optoelectronic applications. Herein, we have synthesized monolayered silicon-doped graphene (SiG) with large surface area using a chemical vapor deposition method. Raman and X-ray photoelectron spectroscopy measurements demonstrate that the silicon atoms are doped into graphene lattice at a doping level of 2.7-4.5 at%. Electrical measurements based on a field effect transistor indicate that the band gap of graphene has been opened via silicon doping without a clear degradation in carrier mobility, and the work function of SiG, deduced from ultraviolet photoelectron spectroscopy, was 0.13-0.25 eV larger than that of graphene. Moreover, when compared with the graphene/GaAs heterostructure, SiG/GaAs exhibits an enhanced performance. The performance of 3.4% silicon doped SiG/GaAs solar cell has been improved by 33.7% on average, which was attributed to the increased barrier height and improved interface quality. Our results suggest that silicon doping can effectively engineer the band gap of monolayered graphene and SiG has great potential in optoelectronic device applications.

Rapid and facile synthesis of graphene oxide quantum dots with good linear and nonlinear optical properties

“…4b, the band gap of the as prepared GOQDs is 3.2 eV. Pure graphene is reported to be a zero band gap material [37]. The observed band gap for the as prepared graphene oxide quantum dots could be attributed to its surface defects.…”

Emerging Bottom‐Up Strategies for the Synthesis of Graphene Nanoribbons and Related Structures

“…Kurzaufsätze performed on aconjugated polymer backbone.T his method, in combination with the Scholl reaction, proves to be very efficient to prepare PA Hs [70] and GNR. [71] When polymer 15 b was used as the precursor,abenzannulation-Scholl sequence gave [13] A GNR 16 b (3p + 1f amily) that showed ambipolar transport properties in FETs. [72] Them ain limitation for the use of such wide GNR is the very low solubility in common organic solvents,m aking the solution processing rather difficult.…”

“…[11] Moreover,s ince graphene is as emi-metal (no band gap), electrons can move freely into its whole structure reaching charge mobility up to 200 000 cm 2 V À1 s À1 . [12] However,the conducting nature of graphene impedes the fabrication of electronic switching devices due to the lack of aband gap.Many ways have been tested to induce aband gap in graphene such as doping, [13] introduction of defects [14] and chemical functionalization, [15] but they often suffer whether from harsh conditions or scale-up problems that limit widespread applications and reproducibility.Aninteresting way to open aband gap in graphene is to cut it into narrow strips with awidth smaller than 10 nm, leading to graphene nanoribbons (GNRs). [16] At that scale,t he quantum confinement of the electrons along the edges of the GNR opens ab and gap, which becomes inversely proportional to its width.…”

First principle and tight-binding study of strained SnC

“…Among these, graphene shows interesting electronic and transport properties but its technological applications are limited due to the negligible electronic band gap at the K point. Since the band gap at the Fermi level is essential for controlling the conductivity in electronic devices, many studies have been made in order to open up the energy band gap of graphene [1][2][3][4]. Contrary to the graphene, some group IV graphenelike 2D structures, i.e., silicene [5,6], germanene [6][7][8], stanene [8][9][10] and their binary compounds [11][12][13][14][15][16] have energy band gap which enable the possible technological applications.…”