Organic thin film phototransistors: Materials and mechanism

Yong Young Noh, Dong Yu Kim, Yuji Yoshida, Kiyoshi Yase, Byung Jun Jung, Eunhee Lim, Hong Ku Shim

Research output: Contribution to journalConference articlepeer-review

2 Scopus citations


Highly photosensitive organic phototransistors (OPTs) with an organic thin film transistors configuration based on a biphenyl end capped fused bithiophene oligomer (BPTT) and copper phthalocyanine (CuPC) were prepared. The measured maximum responsivity and the ratio of photocurrent to dark current (I Ph/IDark) in BPTT and CuPC OPTs were 82 A/W, 2 A/W and 2.0 × 105, 1000 under 365 nm UV light with 1.55 mW/cm2, respectively. The prepared OPTs showed a photocurrent response similar to the photo to current conversion efficiency (IPCE) spectrum of BPTT and CuPC. The main mechanisms responsible for photocurrent amplification in the devices were examined by comparing theoretical and measured data. The photovoltaic (turn-on) and photoconductive effect (turn-off) of the OPTs were determined by fitting to theoretical equations. The findings confirmed that the operation of the OPTs followed as photovoltaic (turn-on state) and photo-conductive (turn-off state) behaviors.

Original languageEnglish
Article number25
Pages (from-to)172-182
Number of pages11
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 2005
EventOrganic Photonic Materials and Devices VII - San Jose, CA, United States
Duration: 24 Jan 200526 Jan 2005


  • Organic photodiodes
  • Organic phototransistors
  • Organic thin film transistors


Dive into the research topics of 'Organic thin film phototransistors: Materials and mechanism'. Together they form a unique fingerprint.

Cite this