The Study Of Electron-selective Contact Characteristics Of Titanium Carbide And Its Application In Crystalline Silicon Solar Cells

Crystalline silicon solar cells stand as one of the most widely adopted solar cell technologies in contemporary applications.Despite considerable strides in efficiency and reliability,the continuous pursuit of enhancing performance remains a primary focal point for research and development efforts.Within the realm of crystalline silicon solar cells,the concept of carrier-selective contacts assumes a pivotal role.Its fundamental objective revolves around achieving the selective harvesting and transportation of electrons or holes,thereby minimizing carrier recombination and transport losses.Consequently,this leads to an augmentation of the overall conversion efficiency of the solar cell.Research and innovations pertaining to this domain play an indispensable role in the ongoing evolution of solar cell technology,with electron transport layers comprising a substantial component thereof.This study systematically explores carrier-selective transport mechanisms and objectively synthesizes the performance characteristics of various electron-selective transport layer materials.Specifically,this study investigates a novel electron-selective contact material—titanium carbide（Ti C_x）.The investigation covers fabrication,property characterization,device performance evaluation,as well as an objective assessment of the thermal and environmental stability of Ti C_x.First,Ti C_x thin films were synthesized using electron beam evaporation and RF magnetron sputtering methodologies.An in-depth analysis focused on structural,optical,and electrical properties,emphasizing electron-selective transport characteristics.The thin films predominantly exhibited an amorphous phase,with objectively low work function and wide bandgap,facilitating low-barrier electron transport and high-barrier hole blocking.Subsequently,these Ti C_x thin films were applied as full-area electron-selective rear contacts in n-type crystalline silicon solar cells,resulting in excellent electron-selective transport capability with low contact resistivity of 17.74 mΩ·cm2and 4.24 mΩ·cm2,respectively.Solar cells featuring Ti C_x electron transport layers prepared via RF magnetron sputtering achieved a notable conversion efficiency of 17.37%without rear passivation.Additionally,this study fabricated self-assembled single-layer two-dimensional Ti₃C₂T_x-MXene films,featureing ultra-low work function and wide bandgap.These films were subsequently used as full-area electron-selective rear contacts in n-type crystalline silicon solar cells,achieving a low contact resistivity of 22.64 mΩ·cm2and an impressive solar cell conversion efficiency of 16.46%.Finally,this study conducted an assessment of the thermal stability and environmental resilience of Ti C_x films produced through RF magnetron sputtering and self-assembled single-layer Ti₃C₂T_x-MXene films.When subjected to high-temperature treatments（770°C annealing）and various environmental assessments,the outcomes objectively demonstrated the remarkable stability and reliability of RF magnetron-sputtered Ti C_x,indicating the posibilty of practical industrial applications.In summary,this study represents a pioneering exploration into the realm of transition metal carbides,with a specific focus on titanium carbide,as a novel electron-selective contact material tailored for crystalline silicon solar cells.The advancements made in material synthesis,property characterization,and device implementation pave the way for achieving highly thermally stable and environmentally robust high-efficiency crystalline silicon solar cells.Furthermore,the successful integration of two-dimensional MXene-based materials into crystalline silicon solar cells,achieving the highest reported conversion efficiency among MXene-based electron transport layer solar cells,provides invaluable insights for the future evolution of solar cell technology.