Large-area epitaxial growth of 2D ZrS2(1−x)Se2x semiconductor alloys with fully tunable compositions and bandgaps for optoelectronics全组分/带隙可调的二维ZrS2(1−x)Se2x半导体合金的外 延生长及其光电应用

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 ZrS{in2(1−{itx})}Se{in2x} alloy films with fully tunable composition on sapphire substrates {itvia} a facile single-step chemical vapor deposition method. The ZrS{in2(1−{itx})}Se{in2{itx}} 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 ZrS{in2(1−{itx})}Se{in2{itx}} (0001)[10–10]∥sapphire (0001)[11–20]. The bandgap of ZrS{in2(1−{itx})}Se{in2{itx}} alloy exhibits a pronounced bowing behavior with continuously tunable bandgaps from 1.86 to 1.15 eV, depending on the Se composition. The ZrS{in2(1−{itx})}Se{in2{itx}}-based photodetectors demonstrate a sensitive photoresponse to visible light with a fast response time of ∼100 µs, and their performances are significantly improved as the Se composition decreases. This work provides an efficient way to synthesize ZrS{in2(1−{itx})}Se{in2{itx}} alloys with fully tunable bandgaps, providing great flexibility in designing TMD-based optoelectronic devices.