Low-temperature, inkjet printed p-type copper(i) iodide thin film transistors

Abstract

Low temperature fabrication of printed p-type CuI TFTs was reported for the first time.

Room‐Temperature Solution‐Synthesized p‐Type Copper(I) Iodide Semiconductors for Transparent Thin‐Film Transistors and Complementary Electronics

“…More importantly, CuI has much higher hole mobility (43.9 cm 2 V −1 s −1 in bulk material) compared with CuSCN and other p‐type oxide semiconductors due to smaller effective hole mass ( m h = 0.3 m 0 , where m 0 is the free electron mass) . This m h is ≈1 order of magnitude smaller than that of CuMO 2 ( m h = 2.6 m 0 ) and is close to the effective electron mass of In 2 O 3 (see Table S1 in the Supporting Information) …”

“…Since the first report by Bädeker in 1907 using vapor iodization, preparation of CuI thin films has been performed using a variety of methods, including sputtering, thermal evaporation, pulsed laser deposition, solid iodination, and solution processes . Solution processing has become a promising alternative to conventional vacuum‐based techniques for large‐scale applications, providing simpler and higher throughput manufacturing at relatively low cost.…”

“…In contrast, crystallized CuI films can be deposited from solution at low temperatures (≤100 °C) . However, despite many potential advantages, CuI has been barely used as a semiconducting channel component for TFTs, mainly due to the high hole concentration and subsequent uncontrollable conductivity of pristine CuI. The TFT semiconductor layer should possess low intrinsic carrier concentration for large on/off current modulation.…”

Defect‐Controlled Copper Iodide: A Promising and Ecofriendly Thermoelectric Material

“…This is av ersatile material that has been attractive in many research fields in the past few decades. [19][20][21][22] CuI is aw ide band gap ( % 3.1 eV) semiconductor that is p-type in nature and that findsm any applications in electronics and optoelectronics. [23,24] Being an inorganic compound, its chemistry allowsi tt or eadily coordinate with many organic ligands and this has resulted in CuIbased hybrid clusters with tremendousl uminescentp roperties.…”

Electronic Properties of Copper(I) Thiocyanate (CuSCN)

“…[62] It is also noteworthy to acknowledge copper iodide (CuI) as it is a well-known p-type metal halide also based on Cu(I) and has been employed in several device applications as a hole-transporting layer. [63][64][65][66] Although the conductivity of γ-CuI is electronic, α-CuI and β-CuI also show strong ionic conductivity [67] and may present a challenge in the development of electronic devices. However, a full discussion on CuI is beyond the scope of this work as it is a common metal halide and does not possess the quasi-molecular nature as in the case of pseudohalides.…”