Highly-efficient full van der Waals 1D p-Te/2D n-Bi
Continuous miniaturization of semiconductor devices is the key to boosting modern electronics development. However, such downscaling strategy has been rarely utilized in photoelectronics and photovoltaics. Here, in this work, a full-vdWs 1D p-Te/2D n-Bi 2 O 2 Se heterodiode with a rationally-designed nanoscale ultra-photosensitive channel is reported. Enabled by the dangling bond-free mixed-dimensional vdWs integration, the Te/Bi 2 O 2 Se type-II diodes show a high rectification ratio of 3.6×10 4 . Operating with 100 mV reverse bias or in a self-power mode, the photodiodes demonstrated excellent photodetection performances, including high responsivities of 130 A W −1 (100 mV bias) and 768.8 mA W −1 (self-power mode), surpassing most of the reports of other heterostructures. More importantly, a superlinear photoelectric conversion phenomenon is uncovered in these nanoscale full-vdWs photodiodes, in which a model based on the in-gap trap-assisted recombination is proposed for this superlinearity. All these results provide valuable insights in light-matter interactions for further performance enhancement of photoelectronic devices.
1 . A method of forming heterodiodes, comprising:
obtaining a first substrate with at least one nanosheet, wherein the first substrate is formed of Mica and wherein the at least one nanosheet is made of bismuth oxyselenide (Bi 2 O 2 Se);
spin-coating a layer over the substrate and at least one nanosheet, wherein the layer is made of polymethyl methacrylate;
peeling off the layer from the substrate removing the at least one coupled nanosheet and forming a peeled-off layer;
obtaining a second substrate with at least one nanowire fabricated on the second substrate, wherein the second substrate is made of silicon dioxide/silicon and wherein the at least one nanowire is made of tellurium;
aligning the peeled-off layer with the second substrate;
pressing the peeled-off layer to the second substrate;
heating the peeled-off layer and the second substrate; and
removing the peeled-off layer from the second substrate leaving the at least one nanosheet on the second substrate forming at least one heterostructure.
2 . The method of claim 1 , wherein aligning the peeled-off layer with the second substrate comprises:
aligning at least a portion of the nanosheet coupled to the peeled-off layer with the at least one nanowire on the second substrate.
3 . The method of claim 1 , wherein removing the peeled-off layer from the second substrate leaving the at least one nanosheet on the second substrate comprises:
leaving the at least one nanosheet on the second substrate positioned over at least a portion of the at least one nanowire.
4 . The method of claim 1 , wherein the at least one heterostructure is made of bismuth oxyselenide and tellurium.
5 . The method of claim 4 , wherein the at least one heterostructure comprises:
a nanowire; and
a nanosheet coupled to at least a portion of the nanowire.
6 . The method of claim 1 , wherein the peeling off step further comprising:
detaching the at least one nanosheet from the first substrate by a wet transfer method.
7 . The method of claim 1 , wherein the peeling off step further comprising:
dispersing at least one nanowire by minor ultrasonication.
8 . The method of claim 1 , wherein forming heterodiodes comprises chemical vapor deposition.
9 . The method of claim 1 , further comprising:
patterning source/drain regions of at least one heterostructure by standard electron-beam lithography.
10 . The method of claim 1 , wherein the peeling off step further comprising:
detaching the at least one nanosheet and the at least one nanowire using a PMMA solution and liquid anhydrous ethanol.