New air-stable solution-processed organic n-type semiconductors based on sulfur-rich core-expanded naphthalene diimides

Highly Sensitive Chemical‐Vapor Sensor Based on Thin‐Film Organic Field‐Effect Transistors with Benzothiadiazole‐Fused‐Tetrathiafulvalene

“…Compared to that of 1 in solution, the absorption spectrum of the thin‐film of 1 is obviously red‐shifted. According to previous reports,32, 38 such spectral shift can be attributed to the intermolecular interactions within thin‐film of 1 . The optical energy gap ( E gopt ) for 1 was estimated to be 1.9 eV based on the onset of absorption of the film.…”

“…The hole mobility of OFETs with 1 can reach as high as 0.73 cm 2 V −1 S −1 with on/off ratio up to 10 5 . Note that these device performance data are the highest reported so far among the thin film OFETs with TTF derivatives 29–33. For instance, the hole mobility of thin‐film OFETs with DB‐TTF was reported to be 0.06 cm 2 V −1 S −1 29a, 39…”

“…Moreover, the hole mobility is varied with the substrate temperature; it increases by increasing the substrate temperature from 20 to 30 °C, but it decreases by further increasing the substrate temperature to 40 °C (see Table 1). According to previous studies,29–33 the carrier mobility of OFETs is influenced by thin film‐morphology and intermolecular packing. Figure depicts the AFM images of thin films of 1 deposited at different temperatures and the respective XRD patterns.…”

“…Thus, the construction of selective OFET‐based sensors with TTF derivatives as the active layers is anticipated by taking advantage of the electroactive features of TTF derivatives. In fact, OFETs based on TTF derivatives have been investigated,28–33 and the corresponding single‐crystal and thin‐film transistors exhibit high mobilities up to 10 and 0.64 cm 2 V −1 s −1 , respectively 28, 29. However, the strong electron‐donating property of TTF derivatives leads to easy doping of their thin films by oxygen,34, 35 resulting in high off‐state conductivity (low on/off ratio), and preventing their application in OFET‐based sensors with high sensitivity.…”

Selenium-Containing Fused Bicyclic Heterocycle Diselenolodiselenole: Field Effect Transistor Study and Structure–Property Relationship

“…10,11,12 The contact between small 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3 molecules in the solid state and degree of conjugation determined the charge-carrier mobility. 13,14 Among the several sets of conjugated materials, sulfur-based conjugated systems 15,16,17,18 are highly explored as p-type semiconducting materials. 19,20,21 Recently, selenium-based conjugated systems are being explored.…”