Broadband light absorption and photoresponse enhancement in monolayer WSe2 crystal coupled to Sb2O3 microresonators

Monolayer (1L) transition metal dichalcogenides (TMDCs) have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps (1.5-2.2 eV) and strong light-matter interactions. Unfortunately, their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response. Here, we report the triangular Sb2O3 microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe2 crystal via coexisting Fabry-Perot and whispering gallery type resonances. As an example of demonstration, 1L WSe2 crystal coupled to Sb(2)O(3 )microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared (NIR) one of more than 50%. For application of 1L WSe2 in photodetection, incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by similar to 10(4) order and expanded NIR one of more than 400 mA.W-1. Similar results have been observed in the other 1L W(Mo) dichalcogenides coupled to Sb(2)O(3 )microresonators. This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.

Automated summary

Monolayer transition metal dichalcogenides have attracted significant interest as promising materials in atomic-scale optoelectronic devices. However, their practical applications are limited by low visible light absorption and negligible infrared response. In this study, the researchers have successfully enhanced light absorption and photoresponse in monolayer WSe2 crystals by growing triangular Sb2O3 microresonators on their surfaces. The introduction of Sb2O3 microresonators led to significantly enhanced visible light responsivity and expanded near infrared absorption. This work provides a new route for the development of high-performance monolayer TMDCs-based optoelectronic devices.