High‐Performance and Reliable Lead‐Free Layered‐Perovskite Transistors

Abstract

Perovskites have been intensively investigated for their use in solar cells and light‐emitting diodes. However, research on their applications in thin‐film transistors (TFTs) has drawn less attention despite their high intrinsic charge carrier mobility. In this study, the universal approaches for high‐performance and reliable p‐channel lead‐free phenethylammonium tin iodide TFTs are reported. These include self‐passivation for grain boundary by excess phenethylammonium iodide, grain crystallization control by adduct, and iodide vacancy passivation through oxygen treatment. It is found that the grain boundary passivation can increase TFT reproducibility and reliability, and the grain size enlargement can hike the TFT performance, thus, enabling the first perovskite‐based complementary inverter demonstration with n‐channel indium gallium zinc oxide TFTs. The inverter exhibits a high gain over 30 with an excellent noise margin. This work aims to provide widely applicable and repeatable methods to make the gate more open for intensive efforts toward high‐performance printed perovskite TFTs.

Reduction of Hysteresis in Hybrid Perovskite Transistors by Solvent-Controlled Growth

“…Reduced hysteresis in SCG MAPbI 3 TFTs was thus consistent with reduced drift-diffusion of I − due to the effective reduction in the total number of defects and grain boundaries. These results were consistent with a previous report on lead-free layered perovskite transistors where grain boundary passivation and grain size enlargement were found to reduce hysteresis and increase TFT reproducibility and reliability [ 50 ].…”

Key Roles of Trace Oxygen Treatment for High‐Performance Zn‐Doped CuI p‐Channel Transistors

“…Therefore, recent attentions have focussed on exploring alternative inorganic p‐type semiconductors with optoelectrical properties comparable to those of n‐type oxide semiconductors. [ 7–10 ] Among these, copper iodide (CuI) is the most promising candidate because of its high Hall mobility (>40 cm 2 V −1 s −1 ), full transparency in the visible range with a wide band gap ( E g ) of ≈3 eV, and amorphous structure with component engineering. [ 11,12 ] CuI has been widely used in diodes, thermoelectric devices, and as a transparent p‐type conducting electrode and hole‐transport layer in solar cells.…”

“…Therefore, recent attentions have focussed on exploring alternative inorganic p-type semiconductors with optoelectrical properties comparable to those of n-type oxide semiconductors. [7][8][9][10] Among these, copper iodide (CuI) is the most promising candidate because of its high Hall mobility (>40 cm 2 V −1 s −1 ), full transparency in the visible range with a wide band substrates, constructing a bottom-gate top-contact device structure with 40 nm Au source/drain electrodes. The as-deposited Zn-doped CuI TFTs exhibited enhancement mode p-channel characteristics with a μ sat of 1.4 cm 2…”

Recent progress toward highly efficient tin‐based perovskite (ASnX3) solar cells

“…The layer structure can be observed by transmission electron microscope. [ 170 ] To reduce the surface energy of crystalline system during the annealing process, the grains grow gradually meanwhile vertically oriented Sn‐based film is formed. The introduction of 12 mol% PEACl leads to 9.1% PCE with the structure of FTO/NiO x /FASnI 3 ‐10 mol% SnF 2 /C 60 /BCP/Ag.…”