Small Molecule/Polymer Blend Organic Transistors with Hole Mobility Exceeding 13 cm² V⁻¹ s⁻¹

Hybrid complementary circuits based on p-channel organic and n-channel metal oxide transistors with balanced carrier mobilities of up to 10 cm2/Vs

“…In addition, the charge carrier mobilities of both organic and metal oxide TFTs have now surpassed the benchmark mobility of 10 cm 2 /Vs, a value far superior to incumbent amorphous Si TFTs. [9][10][11][12] Despite their unique attributes, organic and metal oxide semiconductors suffer from a common drawback, specifically their unipolar nature. For example, although a large number of high performance p-type organic semiconductors are readily available, their n-type counterparts are lacking in performance and stability.…”

“…[27][28][29][30] Here, we report the development of complementary logic inverters (NOT gates) based on combination of organic and metal oxide TFTs processed from solution-phase at temperatures in the range 100-200 C. Both the types of devices exhibit balanced hole and electron transport with mobility values in the range of 5-10 cm 2 /Vs. These high mobilities are achieved through the use of a third generation p-type organic blend semiconductor 11 and an n-type isotype In 2 O 3 / ZnO heterojunction, 7 for the p-channel and n-channel TFTs, respectively. By combining the p-and n-channel TFTs, we Authors to whom correspondence should be addressed.…”

“…The molecular dopant C 60 F 48 was then added at 1% molar weight following the previously described procedures. 11 Figure 1(a) shows the chemical structures of the various materials used. The wafers of degenerately n-doped Si with 400 nm-thick SiO 2 acting as the gate and dielectric, respectively, were employed for the fabrication of discrete bottom-gate, top-contact (BG-TC) metal oxide TFTs ( Figure 1(b)), while organic TFTs were fabricated on glass substrates using a top-gate, bottom-contact (TG-BC) architecture (Figure 1(c)) using the previously described procedures.…”

“…The wafers of degenerately n-doped Si with 400 nm-thick SiO 2 acting as the gate and dielectric, respectively, were employed for the fabrication of discrete bottom-gate, top-contact (BG-TC) metal oxide TFTs ( Figure 1(b)), while organic TFTs were fabricated on glass substrates using a top-gate, bottom-contact (TG-BC) architecture (Figure 1(c)) using the previously described procedures. 11 All the substrates were cleaned prior to materials deposition by ultrasonication in baths of deionised water, acetone and 2-propanol for 10 minutes each and were subjected to UVozone for 15 min. The In 2 O 3 precursor formulation was spincoated onto Si þþ /SiO 2 wafers at 4000 rpm for 30 s followed by thermal annealing at 200 C in air for 1 h. The In 2 O 3 /ZnO heterojunction was completed with the spin coating of the top ZnO layer.…”

“…We have chosen organic semiconducting small molecule/polymer blends, as in recent years they have been shown to outperform the majority of organic semiconductors in TFTs. 11,37,38 The excellent performance of such blend systems is attributed to the vertical phase separation of the two materials during solvent evaporation, where the small molecule diffuses to the surface of the film, leading to the formation of a highly crystalline channel layer. This unique microstructure has been shown to facilitate low conductivity grain boundaries and as a result exhibits excellent hole transport characteristics.…”