透明、可撓式、自供電的二維材料及自組裝極性單層光偵測器

Abstract

在光偵測器中，可彎曲性、透明和無需外加電壓即可操作的能力是三個理想的特性。在此研究中，我們提出並展示了一種由全二維材料製成的超薄、可彎曲性、自供電和透明的光偵測器。該元件是由一層石墨烯作為透明電極，單層的二硫化鎢(WS2)作為吸光層，還包含了自組裝的P3HT-COOH極性單分子層(SAM)，用以提供元件中的內建電場，以及鍍有氧化銦錫、可彎曲的聚對苯二甲酸乙二酯(PET)基板組成。憑藉所選材料的透明特性和自組裝單層的極性特性，可以實現一種透明的自供電光偵測器。在可見光範圍內，此光偵測器的平均透射率約為67%。在無外加偏壓下，該偵測器量測出 1.58 mA∙W-1的光響應度以及 3.29 × 109 Jones的探測率。除此之外，這個可彎曲的光電探測器在經過150次的彎曲循環後在光響應度上無顯著的變化，並且在彎曲時仍可以運作。通過結合上述特性，這種基於全二維材料的光偵測器為開發先進的光電子技術提供了一個具有吸引力的選擇。

Flexibility, transparency and the capability to operate without external power supply are three desirable features for the practical application of advanced photodetectors. In this work, an ultrathin, flexible, self-powered, and transparent photodetector made with all two-dimensional (2D) materials is proposed and demonstrated. This device consists of a layer of graphene serving as a transparent electrode, a single-layer tungsten disulfide (WS2) acting as a light-absorbing layer, and a self-assembled P3HT-COOH polar monolayer (SAM) to provide an additional built-in electric field, and an indium tin oxide-coated polyethylene terephthalate (PET) flexible substrate. The average transmittance in the visible light regime is around 67%. Under zero bias voltage, the photodetector exhibits a responsivity of 1.58 mA∙W-1 and a detectivity of 3.29 × 109 Jones. Additionally, this flexible photodetector demonstrates good retention, retaining its original responsivity magnitude after 150 bending cycles without too much significant change. Based on the aforementioned properties, this all 2D material-based ultrathin, transparent, flexible, and self-powered photodetector offers an attractive option for developing advanced optoelectronic technologies.