Large-area epitaxial growth of 2D ZrS2(1-x)Se2x semiconductor alloys with fully tunable compositions and bandgaps for optoelectronics

Bandgap engineering of transition metal dichalcogenides (TMDs) is significant for broadening their applications in electronics and optoelectronics devices. Herein, we report the new epitaxial growth of large-area uniform ZrS2(1-x)Se2x alloy films with fully tunable composition on sapphire substrates via a facile single-step chemical vapor deposition method. The ZrS2(1-x)Se2x alloys exhibit good single crystallinity and epitaxial quality, as well as uniform elemental distribution, and the epitaxial relationship with the substrate is determined to be ZrS2(1-x)Se2x (0001)[10-10]parallel to sapphire (0001)[11-20]. The bandgap of ZrS2(1-x)Se2x alloy exhibits a pronounced bowing behavior with continuously tunable bandgaps from 1.86 to 1.15 eV, depending on the Se composition. The ZrS2(1-x)Se2x-based photodetectors demonstrate a sensitive photoresponse to visible light with a fast response time of similar to 100 mu s, and their performances are significantly improved as the Se composition decreases. This work provides an efficient way to synthesize ZrS2(1-x)Se2x alloys with fully tunable bandgaps, providing great flexibility in designing TMD-based optoelectronic devices.

Automated summary

In this study, a facile single-step chemical vapor deposition method was used to grow large-area uniform ZrS2(1-x)Se2x alloy films on sapphire substrates, with fully tunable composition. The alloys exhibited good single crystallinity, epitaxial quality, and uniform elemental distribution. The bandgap of the ZrS2(1-x)Se2x alloy could be continuously tuned from 1.86 to 1.15 eV, depending on the Se composition. ZrS2(1-x)Se2x-based photodetectors showed a sensitive photoresponse to visible light with a fast response time of about 100 μs.