Broadband phototransistors realised by incorporating a bi-layer perovskite/NIR light absorbing polymer channel

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2019, Vol.7 (16), p.488-4816
• Main Authors: Li, Ning, Lei, Yanlian, Chan, Wing Kin Edward, Zhu, Furong
• Format: Article
• Language: English
• Subjects: Absorption; Broadband; Charge efficiency; Charge transport; Infrared radiation; Light; Low voltage; Luminous intensity; Perovskites; Photoconductivity; Phototransistors; Polymers
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c8tc06229c

High performing ultraviolet (UV) to near infrared (NIR) light broadband phototransistors (PTs) are realised by incorporating a bi-layer methylammonium lead triiodide (MAPbI 3 ) perovskite/NIR light absorbing diketopyrrolopyrrole-dithienylthieno[3,2- b ]thiophene (DPP-DTT) polymer channel. The bi-layer MAPbI 3 /DPP-DTT channel has the advantages of the (1) complementary absorption and (2) high charge transport efficiency of the two materials. The on- and off-state transfer characteristics of the bi-layer MAPbI 3 /DPP-DTT channel PTs, in the presence of different intensities of UV, visible and NIR light, were analyzed. The bi-layer MAPbI 3 /DPP-DTT channel PTs possess simultaneously a specific detectivity ( D* ) of >10 9 Jones over the UV to visible light wavelength range and a high D * of >10 7 Jones over the NIR light wavelength range. The broadband PTs can be operated at a low voltage (−1 V) without showing persistent photoconductivity behavior. The results are very encouraging. It is anticipated that the bi-layer perovskite/NIR light absorbing polymer channel concept is a very promising approach for realising high performance UV to NIR light broadband PTs. Broadband phototransistors (PTs) with a bi-layer MAPbI 3 /NIR light absorbing polymer channel have the advantages of the complementary absorption and high charge transport efficiency of the two materials. The broadband PTs possess simultaneously a specific detectivity ( D *) of >10 9 Jones over the wavelength range from UV to visible light and a high D * of >10 7 Jones over the NIR light wavelength range.