High-Efficiency Thin-Film Photovoltaics

Transparent Conductive Oxides, Perovskites, and Tandem Structures

The global demand for clean and sustainable energy continues to grow rapidly, driving the development of advanced photovoltaic technologies capable of delivering higher efficiencies, lower costs, and improved scalability. Our research group focuses on high-efficiency thin-film photovoltaics, with particular emphasis on transparent conductive oxides (TCOs), perovskite solar cells, and tandem device architectures. By combining materials science, device engineering, and advanced characterization, we aim to push the performance and stability of next-generation solar technologies.

Thin-Film Photovoltaics: An Overview

Thin-film photovoltaics differ from conventional silicon solar cells in that the active layers are only a few nanometers to micrometers thick. These reduced thicknesses enable several advantages, including lower material consumption, compatibility with lightweight and flexible substrates, and the potential for low-cost large-area manufacturing techniques such as solution processing or vapor deposition.

Despite their thinness, modern thin-film devices can achieve remarkable power conversion efficiencies when material quality, interface engineering, and optical design are carefully optimized. Our work explores new materials and device structures that enhance light absorption, improve charge transport, and reduce recombination losses.

Transparent Conductive Oxides (TCOs)

Transparent conductive oxides play a crucial role in nearly all thin-film photovoltaic devices. These materials serve as electrically conductive electrodes while simultaneously allowing light to pass through to the active layers. Achieving high optical transparency together with low electrical resistance requires precise control of composition, doping, and microstructure.

Our research investigates both established and emerging TCO materials. We study deposition methods, surface morphology, and interface properties, with the goal of improving conductivity without sacrificing transparency. Particular attention is given to the interaction between TCO layers and adjacent functional materials, since interface quality strongly influences overall device efficiency and long-term stability.

In addition to conventional planar electrodes, we also explore nanostructured and textured TCO surfaces designed to enhance light trapping. By increasing the optical path length within the absorber layer, such structures can significantly improve the performance of thin devices.

Perovskite Solar Cells

Metal-halide perovskites have emerged as one of the most promising photovoltaic materials of the past decade. Their exceptional optical absorption, long carrier diffusion lengths, and tunable bandgaps have enabled rapid improvements in device efficiency, making them strong candidates for next-generation solar technologies.

Our group works on several aspects of perovskite photovoltaics, including material synthesis, thin-film formation, and interface engineering. A key challenge in perovskite solar cells is achieving high efficiency while maintaining operational stability under real-world conditions such as humidity, temperature variations, and prolonged illumination. To address this, we investigate strategies such as compositional engineering, defect passivation, and advanced encapsulation techniques.

We also study charge-transport layers and electrode materials that improve carrier extraction and reduce energy losses. By carefully controlling the interfaces between layers, it is possible to enhance both efficiency and device lifetime.

Tandem Solar Cell Architectures

One of the most effective ways to surpass the efficiency limits of single-junction solar cells is through tandem architectures, in which two or more photovoltaic layers with different bandgaps are stacked together. Each layer absorbs a different portion of the solar spectrum, enabling more efficient use of incident sunlight.

Perovskite materials are particularly well suited for tandem applications because their bandgap can be tuned across a wide range. Our research explores perovskite-based tandems as well as hybrid configurations combining perovskites with other thin-film or crystalline technologies.

Developing high-performance tandem devices requires careful optimization of optical coupling, current matching, and interconnection layers. We investigate advanced recombination layers, transparent electrodes, and optical modeling techniques to maximize energy conversion efficiency while maintaining mechanical and thermal stability.

Characterization and Device Analysis

Understanding the fundamental physical processes that govern device performance is essential for continued progress. Our group employs a broad range of characterization techniques to study material properties, interfaces, and operating devices. These methods allow us to analyze charge transport, recombination mechanisms, defect states, and degradation pathways.

By combining experimental measurements with modeling and simulation, we can identify performance-limiting factors and design strategies to overcome them. This integrated approach enables systematic improvements in both materials and device structures.

Toward Scalable and Sustainable Solar Technologies

Beyond achieving record efficiencies in laboratory devices, our research also considers scalability and environmental impact. We investigate deposition techniques compatible with large-area manufacturing and explore materials and processes that reduce energy consumption and reliance on scarce elements.

Thin-film photovoltaics offer unique opportunities for integration into buildings, vehicles, and portable systems due to their lightweight and flexible nature. Advancing these technologies contributes not only to improved energy generation but also to the broader transition toward sustainable energy systems.

Research Vision

Our long-term vision is to develop photovoltaic technologies that combine high efficiency, long-term stability, and cost-effective manufacturing. By advancing transparent conductive materials, perovskite absorbers, and tandem device architectures, we aim to contribute to the next generation of solar energy solutions.

Through interdisciplinary collaboration and close integration of materials science, physics, and engineering, our work seeks to address both fundamental scientific challenges and practical technological needs.