Graphene/h-BN/ZnO van der Waals tunneling heterostructure based ultraviolet photodetector

Abstract

We report a novel ultraviolet photodetector based on graphene/h-BN/ZnO van der Waals heterostructure. Graphene/ZnO heterostructure shows poor rectification behavior and almost no photoresponse. In comparison, graphene/h-BN/ZnO structure shows improved electrical rectified behavior and surprising high UV photoresponse (1350AW(-1)), which is two or three orders magnitude larger than reported GaN UV photodetector (0.2~20AW(-1)). Such high photoresponse mainly originates from the introduction of ultrathin two-dimensional (2D) insulating h-BN layer, which behaves as the tunneling layer for holes produced in ZnO and the blocking layer for holes in graphene. The graphene/h-BN/ZnO heterostructure should be a novel and representative 2D heterostructure for improving the performance of 2D materials/Semiconductor heterostructure based optoelectronic devices.

Graphene-Based Semiconductor Heterostructures for Photodetectors

“…These results suggest how important the van der Waals interface is for the efficient optoelectronic processes in heterostructure PDs. On the other hand, in graphene/ZnO heterostructures photodiodes [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ], the photogenerated electron/hole pairs were found to be separated by the built-in potential even at zero bias, thereby potentially reducing the DC, resulting in the increase of specific D* [ 61 , 64 , 66 ]. The response of the photodiode was shown to be much faster than that of the phototransistor-type PD by further increasing the built-in electric field under moderate reverse bias [ 57 , 59 , 60 , 62 , 63 ].…”

“…The PD could also monitor the pulse light at high frequencies of 2250 Hz. The PD performance was further improved by employing charge tunneling/blocking interlayer [ 58 ] and by modulating the Schottky barrier through back gating [ 59 ] or external deformation [ 60 , 62 ]. The R was also enhanced up to 1350 A/W at ~5 V by inserting a hexagonal boron nitride (h-BN) layer into the graphene/ZnO Schottky junction [ 58 ].…”

“…The PD performance was further improved by employing charge tunneling/blocking interlayer [ 58 ] and by modulating the Schottky barrier through back gating [ 59 ] or external deformation [ 60 , 62 ]. The R was also enhanced up to 1350 A/W at ~5 V by inserting a hexagonal boron nitride (h-BN) layer into the graphene/ZnO Schottky junction [ 58 ]. The h-BN interface layer reduced the DC by suppressing the electron transfer from graphene to ZnO, and suppressed the recombination of carriers, resulting in the increase of the PC, by holding photogenerated electrons in ZnO.…”

“…Chemical vapor deposition (CVD)-grown graphene was first employed in graphene/Si heterojunctions, resulting in 65% external quantum efficiency (EQE) [ 24 ], which served as the prototype for the subsequent intensive studies on the graphene TCEs-based various kinds of semiconductor hybrid heterojunctions for high-efficiency PDs [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ,…”

Engineered tunneling layer with enhanced impact ionization for detection improvement in graphene/silicon heterojunction photodetectors

“…What’s more, the leakage current induced by the surface states within the GS interface generally results in a low specific detectivity 6 . With the aim to address these issues, interface engineering, such as using the tunneling heterostructures 17 – 19 , introducing the passivation layer 20 – 22 , or modification with quantum dots/nanoparticles 23 , 24 , has been adopted to improve the photo-detection in the GS heterojunction photodetectors. In addition, the integrating of plasmonic nanostructures also has been demonstrated to be an effective strategy to improve the detecting performance via the modified absorption and internal photoemission process 25 , 26 .…”