Tuning the hole transporting layer using the NiO@X₂C (X = W or Mo) composites for polymer solar cells and X-ray detectors

In this paper, we showcased the augmentation in power conversion efficiency (PCE) and photodetectivity of bulk heterojunction (BHJ) organic solar cells and photodetectors through the integration of functionalized metal carbides interacted NiO composites with PEDOT:PSS as a hole transport (HT) material. The 2D metal carbides (Mo₂C and W₂C), quintessential representatives of the MXenes family, integrated NiO were synthesized and employed to tune the HT in BHJ solar cells and photodetectors. These materials exhibit exceptional electronic conductivity, high mobility, enhanced electron extraction, excellent optical transparency, and desirable mechanical properties, rendering them as ideal candidates for enhancing the performance of BHJ devices. The constructed devices with NiO@Mo₂C and NiO@W₂C blended PEDOT:PSS HT achieved a PCE of ∼7.49 % and ∼8.32 %, representing the ∼28 % and ∼43 % improvement, respectively compared to the PCE obtained with the pure PEDOT:PSS active layer (PCE = 5.86 %). Additionally, the photodetector utilizing the NiO@Mo₂C and NiO@W₂C blended PEDOT:PSS HT demonstrated a maximum sensitivity of 2.25 and 2.62 mA/Gy·cm² better than the pure HT under X-ray irradiation. This work suggests the integration of 2D metal carbides integrated NiO into the HT as a promising approach to enhance the efficiency of BHJ devices.