TY - JOUR
T1 - Bithiophene-imide-based polymeric semiconductors for field-effect transistors
T2 - Synthesis, structure-property correlations, charge carrier polarity, and device stability
AU - Guo, Xugang
AU - Ortiz, Rocio Ponce
AU - Zheng, Yan
AU - Hu, Yan
AU - Noh, Yong Young
AU - Baeg, Kang Jun
AU - Facchetti, Antonio
AU - Marks, Tobin J.
PY - 2011/2/9
Y1 - 2011/2/9
N2 - Developing new high-mobility polymeric semiconductors with good processability and excellent device environmental stability is essential for organic electronics. We report the synthesis, characterization, manipulation of charge carrier polarity, and device air stability of a new series of bithiophene-imide (BTI)-based polymers for organic field-effect transistors (OFETs). By increasing the conjugation length of the donor comonomer unit from monothiophene (P1) to bithiophene (P2) to tetrathiophene (P3), the electron transport capacity decreases while the hole transport capacity increases. Compared to the BTI homopolymer P(BTimR) having an electron mobility of 10 -2 cm2 V-1 s-1, copolymer P1 is ambipolar with balanced hole and electron mobilities of ∼10-4 cm2 V-1 s-1, while P2 and P3 exhibit hole mobilities of ∼10-3 and ∼10-2 cm2 V-1 s-1, respectively. The influence of P(BTimR) homopolymer Mn on film morphology and device performance was also investigated. The high Mn batch P(BTimR)-H affords more crystalline film microstructures; hence, 3- increased electron mobility (0.038 cm 2 V-1 s-1) over the low Mn one P(BTimR)-L (0.011 cm2 V-1 s-1). In a top-gate/bottom-contact OFET architecture, P(BTimR)-H achieves a high electron mobility of 0.14 cm2 V-1 s-1, only slightly lower than that of state-of-the-art n-type polymer semiconductors. However, the high-lying P(BTimR)-H LUMO results in minimal electron transport on exposure to ambient. Copolymer P3 exhibits a hole mobility approaching 0.1 cm2 V-1 s-1 in top-gate OFETs, comparable to or slightly lower than current state-of-the-art p-type polymer semiconductors (0.1-0.6 cm 2 V-1 s-1). Although BTI building block incorporation does not enable air-stable n-type OFET performance for P(BTimR) or P1, it significantly increases the OFET air stability for p-type P2 and P3. Bottom-gate/top-contact and top-gate/bottom-contact P2 and P3 OFETs exhibit excellent stability in the ambient. Thus, P2 and P3 OFET hole mobilities are almost unchanged after 200 days under ambient, which is attributed to their low-lying HOMOs (>0.2 eV lower than that of P3HT), induced by the strong BTI electron-withdrawing capacity. Complementary inverters were fabricated by inkjet patterning of P(BTimR)-H (n-type) and P3b (p-type).
AB - Developing new high-mobility polymeric semiconductors with good processability and excellent device environmental stability is essential for organic electronics. We report the synthesis, characterization, manipulation of charge carrier polarity, and device air stability of a new series of bithiophene-imide (BTI)-based polymers for organic field-effect transistors (OFETs). By increasing the conjugation length of the donor comonomer unit from monothiophene (P1) to bithiophene (P2) to tetrathiophene (P3), the electron transport capacity decreases while the hole transport capacity increases. Compared to the BTI homopolymer P(BTimR) having an electron mobility of 10 -2 cm2 V-1 s-1, copolymer P1 is ambipolar with balanced hole and electron mobilities of ∼10-4 cm2 V-1 s-1, while P2 and P3 exhibit hole mobilities of ∼10-3 and ∼10-2 cm2 V-1 s-1, respectively. The influence of P(BTimR) homopolymer Mn on film morphology and device performance was also investigated. The high Mn batch P(BTimR)-H affords more crystalline film microstructures; hence, 3- increased electron mobility (0.038 cm 2 V-1 s-1) over the low Mn one P(BTimR)-L (0.011 cm2 V-1 s-1). In a top-gate/bottom-contact OFET architecture, P(BTimR)-H achieves a high electron mobility of 0.14 cm2 V-1 s-1, only slightly lower than that of state-of-the-art n-type polymer semiconductors. However, the high-lying P(BTimR)-H LUMO results in minimal electron transport on exposure to ambient. Copolymer P3 exhibits a hole mobility approaching 0.1 cm2 V-1 s-1 in top-gate OFETs, comparable to or slightly lower than current state-of-the-art p-type polymer semiconductors (0.1-0.6 cm 2 V-1 s-1). Although BTI building block incorporation does not enable air-stable n-type OFET performance for P(BTimR) or P1, it significantly increases the OFET air stability for p-type P2 and P3. Bottom-gate/top-contact and top-gate/bottom-contact P2 and P3 OFETs exhibit excellent stability in the ambient. Thus, P2 and P3 OFET hole mobilities are almost unchanged after 200 days under ambient, which is attributed to their low-lying HOMOs (>0.2 eV lower than that of P3HT), induced by the strong BTI electron-withdrawing capacity. Complementary inverters were fabricated by inkjet patterning of P(BTimR)-H (n-type) and P3b (p-type).
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U2 - 10.1021/ja107678m
DO - 10.1021/ja107678m
M3 - Article
C2 - 21207965
AN - SCOPUS:79551718807
VL - 133
SP - 1405
EP - 1418
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 5
ER -