Abstract
Organic optical memory devices keep attracting intensive interests for diverse optoelectronic applications including optical sensors and memories. Here, flexible nonvolatile optical memory devices are developed based on the bis[1]benzothieno[2,3-d;2′,3′-d′]naphtho[2,3-b;6,7-b′]dithiophene (BBTNDT) organic field-effect transistors with charge trapping centers induced by the inhomogeneity (nanosprouts) of the organic thin film. The devices exhibit average mobility as high as 7.7 cm2 V−1 s−1, photoresponsivity of 433 A W−1, and long retention time for more than 6 h with a current ratio larger than 106. Compared with the standard floating gate memory transistors, the BBTNDT devices can reduce the fabrication complexity, cost, and time. Based on the reasonable performance of the single device on a rigid substrate, the optical memory transistor is further scaled up to a 16 × 16 active matrix array on a flexible substrate with operating voltage less than 3 V, and it is used to map out 2D optical images. The findings reveal the potentials of utilizing [1]benzothieno[3,2-b][1]benzothiophene (BTBT) derivatives as organic semiconductors for high-performance optical memory transistors with a facile structure. A detailed study on the charge trapping mechanism in the derivatives of BTBT materials is also provided, which is closely related to the nanosprouts formed inside the organic active layer.
Original language | English (US) |
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Article number | 1706647 |
Journal | Advanced Materials |
Volume | 30 |
Issue number | 13 |
DOIs | |
State | Published - Mar 27 2018 |
Funding
The authors thank Dr. Yuichi Sadamitsu for providing the BBTNDT and DPhBBTNDT materials and Prof. Kazuo Takimiya for the fruitful discussions. The authors gratefully acknowledge the support from the General Research Fund (GRF) under Grant Nos. HKU 17204517, 17200314, and 17264016, the National Natural Science Foundation of China (NSFC), and the Research Grants Council (RGC) of Hong Kong Joint Research Scheme under Grant No. N_HKU715/14.
Keywords
- optical images
- optical memory transistors
- organic semiconductors
- structural inhomogeneity
ASJC Scopus subject areas
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering