Progress on Crystal Growth of Two-Dimensional Semiconductors for Optoelectronic Applications

Abstract

Two-dimensional (2D) semiconductors are thought to belong to the most promising candidates for future nanoelectronic applications, due to their unique advantages and capability in continuing the downscaling of complementary metal-oxide-semiconductor (CMOS) devices while retaining decent mobility. Recently, optoelectronic devices based on novel synthetic 2D semiconductors have been reported, exhibiting comparable performance to the traditional solid-state devices. This review briefly describes the development of the growth of 2D crystals for applications in optoelectronics, including photodetectors, light-emitting diodes (LEDs), and solar cells. Such atomically thin materials with promising optoelectronic properties are very attractive for future advanced transparent optoelectronics as well as flexible and wearable/portable electronic devices.

MoS2/h-BN/Graphene Heterostructure and Plasmonic Effect for Self-Powering Photodetector: A Review

“…Generally, 2D materials have great potential for high-performance photodetectors due to their high crystal quality and unique properties in both electronic and optical aspects such as tunable bandgaps with thickness variations [ 25 ], as well as strong covalent bonding between molecular layers with relatively low van Der Waals (vdW) at the interlayer [ 26 ]. Generally, 2D materials have large surface-to-volume ratios [ 19 ] with ultra-thin lattice structures [ 27 ] and flexible integrability [ 28 ]. Moreover, 2D materials are sensitive to light, heat and ambient, which make them suitable for broader spectrum detection from the infrared to ultraviolet regime [ 4 , 11 , 27 ].…”

“…Generally, 2D materials have large surface-to-volume ratios [ 19 ] with ultra-thin lattice structures [ 27 ] and flexible integrability [ 28 ]. Moreover, 2D materials are sensitive to light, heat and ambient, which make them suitable for broader spectrum detection from the infrared to ultraviolet regime [ 4 , 11 , 27 ]. Specific crystal structure and atomic layer stacking sequence, especially in TMDs, can vary the phases of 2D materials from the range of metallic, semiconducting, superconducting and insulating [ 29 ].…”

“…Graphene is an sp 2 -hybridized carbon atom in a honeycomb lattice structure [ 31 ] that has a monoatomic layer thickness, high carrier mobility [ 6 , 27 , 29 , 32 , 33 ], broadband absorption from visible to infrared regime [ 6 , 27 , 32 , 33 , 34 ], high thermal conductivity [ 29 ], ultra-fast performance [ 12 , 34 ], high mechanical strength [ 29 ] and good toughness. It also has a gate tunability effect [ 6 , 33 ] and is a good candidate for high-frequency optoelectronics [ 27 ]. Graphene serves as a transparent electrode with high optical transmittance, large electrical conductivity and tunable work function.…”

“…Although graphene shows excellent properties for light detecting applications, it is limited by low photoresponsivity, detectivity and quantum efficiency due to its low light absorption coefficient and fast recombination rate [ 4 ] with an ultrashort photocarrier lifetime [ 38 ]. These drawbacks are due to the absence of a bandgap in graphene that makes it semi-metallic [ 6 , 27 , 29 ]. Many approaches were explored to tackle this issue, such as graphene bandgap opening with doping method, material engineering to enhance interaction between graphene and device structure engineering [ 14 ].…”

“…Material synthesis and device fabrication, especially involving graphene, MoS 2 and h-BN, were reviewed extensively in [ 6 , 26 , 27 ]. Graphene can be obtained via micro-mechanical cleavage of bulk graphite, CVD and chemical functionalism, as reviewed in [ 6 ].…”