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Amorphous oxide semiconductors (AOSs), specifically those based on ternary cation systems such as Ga-, Si-, and Hf-doped InZnO, have emerged as promising material candidates for application in next-gen transparent electronic and optoelectronic devices. Third cation-doping is a common method used during the manufacturing of amorphous oxide thin film transistors (TFTs), primarily with the intention of suppressing carrier generation during the fabrication of the channel layer of a transistor. However, the incorporation of a third cation species has been observed to negatively affect the carrier transport properties of the thin film, as it may act as an additional scattering center and subsequently lower the carrier mobility from ∼20–40 cm 2 V −1 s −1 of In 2 O 3 or a binary cation system ( i.e. , InZnO) to ∼1–10 cm 2 V −1 s −1 . This study investigates the structural, electrical, optoelectronic, and chemical properties of the ternary cation material system, InAlZnO (IAZO). The optimized carrier mobility (Hall Effect) of Al-doped InZnO is shown to remain as high as ∼25–45 cm 2 V −1 s −1 . Furthermore, Al incorporation in InZnO proves to enhance the amorphous phase stability under thermal stresses when compared to baseline InZnO films. Thin film transistors integrating optimized IAZO as the channel layer are shown to demonstrate promisingly high field effect mobilities (∼18–20 cm 2 V −1 s −1 ), as well as excellent drain current saturation and high drain current on/off ratios (>10 7 ). The high mobility and improved amorphous phase stability suggest strong potential for IAZO incorporation in the next generation of high performance and sustainable optoelectronic devices such as transparent displays. 

Transparent photovoltaics (TPVs) can be integrated into the surfaces of buildings and vehicles to provide point‐of‐use power without impacting aesthetics. Unlike TPVs that target the photon‐rich near‐infrared portion of the solar spectrum, TPVs that harvest ultraviolet (UV) photons can have significantly higher transparency and color neutrality, offering a superior solution for low‐power electronics with stringent aesthetic tolerance. In addition to being highly transparent and colorless, an ideal UV‐absorbing TPV should also be operationally stable and scalable over large areas while still outputting sufficient power for its specified application. None of today's TPVs meet all these criteria simultaneously. Here, the first UV‐absorbing TPV is demonstrated that satisfies all four criteria by using CsPbCl_2.5Br_0.5as the absorber. By precisely tuning the halide ratio during thermal co‐evaporation, high‐quality large‐area perovskite films can be accessed with an ideal absorption cutoff for aesthetic performance. The resulting TPVs exhibit a record average visible transmittance of 84.6% and a color rendering index of 96.5, while maintaining an output power density of 11 W m⁻²under one‐sun illumination. Further, the large‐area prototypes up to 25 cm²are demonstrated, that are operationally stable with extrapolated lifetimes of >20 yrs under outdoor conditions.

 

While metal‐halide perovskite light‐emitting diodes (PeLEDs) hold the potential for a new generation of display and lighting technology, their slow operation speed and response time limit their application scope. Here, high‐speed PeLEDs driven by nanosecond electrical pulses with a rise time of 1.2 ns are reported with a maximum radiance of approximately 480 kW sr⁻¹ m⁻²at 8.3 kA cm⁻², and an external quantum efficiency (EQE) of 1% at approximately 10 kA cm⁻², through improved device configuration designs and material considerations. Enabled by the fast operation of PeLEDs, the temporal response provides access to transient charge carrier dynamics under electrical excitation, revealing several new electroluminescence quenching pathways. Finally, integrated distributed feedback (DFB) gratings are explored, which facilitate more directional light emission with a maximum radiance of approximately 1200 kW sr⁻¹m⁻²at 8.5 kA cm⁻², a more than two‐fold enhancement to forward radiation output.

 

Electrically pumped lasing from hybrid organic–inorganic metal‐halide perovskite semiconductors could lead to nonepitaxial diode lasers that are tunable throughout the visible and near‐infrared spectrum; however, a viable laser diode architecture has not been demonstrated to date. Here, an important step toward this goal is achieved by demonstrating two distinct distributed feedback light‐emitting diode architectures that achieve low threshold, optically pumped lasing. Bottom‐ and top‐emitting perovskite light‐emitting diodes are fabricated on glass and Si substrates, respectively, using a polydimethylsiloxane stamp in the latter case to nanoimprint a second‐order distributed feedback grating directly into the methylammonium lead iodide active layer. The devices exhibit room temperature thresholds as low as ≈6 µJ cm⁻², a peak external quantum efficiency of ≈0.1%, and a maximum current density of ≈2 A cm⁻²that is presently limited by degradation associated with excessive leakage current. In this low current regime, electrical injection does not adversely affect the optical pump threshold, leading to a projected threshold current density of ≈2 kA cm⁻². Operation at low temperature can significantly decrease this threshold, but must overcome extrinsic carrier freeze‐out in the doped organic transport layers to maintain a reasonable drive voltage.