Tuning the Electrical Properties of Titanium Oxide Bilayers Prepared by Atomic Layer Deposition at Different Temperatures

Carrier‐selective contacts prepared by atomic layer deposition (ALD) have received significant attention for developing high‐efficiency solar cells. Herein, the electrical properties of titanium oxide (TiO x ) prepared by ALD are manipulated by modulating the deposition temperature during ALD. Tunable electrical properties are possible due to the existence of oxygen vacancies in TiO x prepared at low deposition temperatures. TiO x layers prepared at 100 and 150 °C provide a low contact resistivity and high passivation performance, respectively. A high carrier selectivity of 13.5 is achieved by stacking the TiO x layers prepared at 100 and 150 °C, compared with a single TiO x layer. Modulating the deposition temperature can, therefore, improve the electrical properties of ALD‐TiO x . This approach can be used to optimize the functionality of ALD‐based materials.