Near-infrared photodetection based on PbS colloidal quantum dots/organic hole conductor

✍ Scribed by Sang Hyuk Im; Jeong Ah Chang; Sung Woo Kim; Sang-Wook Kim; Sang Il Seok

• Book ID: 104076087
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 357 KB
• Volume: 11
• Category: Article
• ISSN: 1566-1199
• DOI: 10.1016/j.orgel.2009.12.021

✦ Synopsis

We have developed Near-infrared (NIR)-sensitive heterojunction cells consisting of n-type PbS colloidal quantum dots (CQDs) (low bandgap) anchored on the nanoporous TiO 2 (np-TiO 2 , high-bandgap), and p-type spiro-OMeTAD (2,2 0 ,7,7 0 -tetrakis(N,N-di-p-methoxyphenylamine)-9,9 0 -spirobifluorene). In these cells, an n-type np-TiO 2 layer acts both as a host that chemically binds to the PbS CQDs and as an electron carrier. The number of PbS CQDs loaded onto the np-TiO 2 layer not only increases the external quantum efficiency (EQE) but also reduces the response time in the NIR region. The performance of these devices increased upon the introduction of a TiO x layer between the PbS CQDs and spiro-OMeTAD followed by heat treatment at 110 °C for 1 min.