We propose that 1 + 1 + 1 triple-junction solar cells can provide an increased efficiency, as well as a higher open circuit voltage, compared to tandem solar cells.

We have studied the fabrication of solution processed aluminum-oxide (AlO_x) gate dielectric at the maximum process temperature of 300 °C for a solution based zinc-tin-oxide (ZTO) thin-film-transistor (TFT). An AlO_x layer was spin-coated from a solution of aluminum chloride (AlCl₃) and then annealed at 300 °C for 1 h. The breakdown electrical field and leakage current density of the AlO_x were found to be ∼4 MV cm⁻¹ and 63 μA cm⁻² at 1 MV cm⁻¹, respectively. The ZTO layer was prepared by spin-coating or inkjet printing as an active layer of the TFT with AlO_x gate dielectric and then annealed at 300 °C for 1 h. The TFT made using spin coating exhibited the field-effect mobility of 33 cm² V⁻¹s⁻¹ in the saturation region, a gate swing of 96 mV dec.⁻¹ and a threshold voltage of ∼1.2 V and the inkjet printed TFT showed a field-effect mobility of 24 cm² V⁻¹s⁻¹.

Highly efficient green, red, and blue perovskite light‐emitting diode based metal‐oxide charge injection layers are demonstrated. This is an important step toward the realization of next‐generation solid‐state lighting and devices for use in full‐color large‐area display applications.