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The efficient separation and extraction of holes can be attributed to the favorable properties possessed by the hole transport layer (HTL). Herein, a novel solution‐processable hybrid HTL based on CuBO2 and Ti3C2Tx MXene (CuBO2@MXene) is developed to enhance the performance of ultraviolet photodetectors (UV PDs). By optimizing the ratio of Ti3C2Tx MXene to CuBO2, the optimized responsivity and detectivity of the UV PDs based on the composite HTL have achieved 184 mA W−1 and 2.88 × 1013 cm Hz1/2 W−1 in self‐powered mode, respectively, and even up to 3.25 × 104 mA W−1 at −1.5 V. This significant improvement in device performance can be attributed to the interlaced architecture of CuBO2@MXene, which ameliorates hole mobility and charge extraction capability while reducing the trap state density of the HTL. The built‐in electric field of the TiO2/CuBO2 heterojunction is strengthened by the incorporation of Ti3C2Tx MXene, thereby significantly reinforcing the photovoltaic effect. Moreover, the lower thermal conductivity of CuBO2@MXene suppresses its pyroelectric effect, weakening the blocking effect of the thermoelectric potential on hole transport and ultimately leading to a remarkable boost in the output current. These results indicate the promising potential of the hybrid CuBO2@MXene HTL for constructing high‐performance optoelectronic devices. [ABSTRACT FROM AUTHOR]

CuAlO2 was synthesized by a hydrothermal method, in which the Cu–O dimers were incorporated by simply altering the ratio of the reactants and the temperature. The incorporation process increases the grain size in CuAlO2, and modulates the work function and binding energies for CuAlO2 due to the partial substitution of Cu+ 3d10 with Cu2+ 3d9 orbitals in the valence band maximum by alloying non-isovalent Cu–O with a CuAlO2 host. Based on the ZnO nanorod arrays (NRs) ultraviolet photodetector, CuAlO2/Cu–O fabricated by the low-cost drop-coating method was used as the p-type hole transport layer. The incorporation of the Cu–O clusters into CuAlO2 lattice to enhance the conductivity of CuAlO2 is an effective way for improving ZnO NRs/CuAlO2 device performance. The photodetectors exhibit significant diode behavior, with a rectification ratio approaching 30 at ±1 V, and a dark saturation current density 0.81 mA cm−2. The responsivity of the ZnO-NRs-based UV photodetector increases from 13.2 to 91.3 mA/W at 0 V bias, with an increase in the detectivity from 2.35 × 1010 to 1.71 × 1011 Jones. Furthermore, the ZnO NRs/[CuAlO2/Cu–O] photodetector exhibits a maximum responsivity of 5002 mA/W at 1.5 V bias under 375 nm UV illumination. [ABSTRACT FROM AUTHOR]