WO3‐Based Electrochromic Distributed Bragg Reflector: Toward Electrically Tunable Microcavity Luminescent Device

The electroresponsive WO3‐based electrochromic distributed Bragg reflectors (ECDBRs) are fabricated by means of one‐step, room temperature glancing‐angle electron‐beam evaporation. The reflectance and Bragg wavelength of ECDBRs can be precisely and reversibly tailored on a large scale by simply applying a small bias voltage (±1.1 V) due to the electrochromic effect of the WO3 layer, and this unique character is utilized to construct an electrically tunable microcavity luminescent device with embedded green CdSe@ZnS quantum dots (QDs). Therefore, large and reversible modulation in terms of photoluminescence (PL) peak intensity (18–335%), PL peak position (from 510.3 to 525.8 nm), and full width at half maximum (from 21.8 to 11.4 nm) from QDs in microcavity are achieved under electrical stimulus. The results will potentially provide a straightforward voltage‐control route toward broadband tunable microcavity electroluminescent and lasing devices.