What Is Holding Back Mass Adoption of Perovskite Solar Cells?

What's Special about Perovskite Solar Cells

Perovskite solar cells represent a young class of photovoltaic devices that have attracted attention within the renewable energy sector. Their name is derived from a crystal structure common in numerous minerals. These new cells absorb light effectively and convert it to electricity with high power conversion efficiency. Many groups have demonstrated power conversion efficiencies competitive with, and even exceeding, those of conventional silicon solar cells. Their potential is attributed to the simple chemical composition and low cost of their materials.

These solar cells have generated interest due to their innovative approach. Their properties render them suitable for integration in diverse settings. In laboratory conditions, perovskite solar cells have been produced via low-temperature solution processing. The same technique may enable roll-to-roll printing on flexible substrates. This process involves methods akin to printing newspapers, which could facilitate cost-effective production. In many situations, these cells can be manufactured on plastic instead of rigid glass. This opens numerous applications, including building-integrated photovoltaics and portable electronics. However, challenges remain regarding the reliable production of these films at scale.

Key Benefits of Perovskite Solar Cells

Among various advantages, perovskite solar cells present several unique benefits over conventional solar cell technologies.

•         High power conversion efficiency: They demonstrate conversion efficiency comparable to silicon-based cells. In several laboratory tests, these cells have achieved close to 25 percent efficiencies.

•         Low cost of manufacturing: Solution processing methods and roll-to-roll techniques are applied during production. Energy consumption and material waste may be diminished using this process compared to high-temperature silicon fabrication.

•         Flexible, lightweight design: Thin, pliable layers allow for integration into building materials and portable electronics. An example of this is that perovskite layers have already been tested on windows and curved surfaces, indicating their adaptability to various conditions.

•         High absorption and tunable bandgap properties: The perovskite material can be engineered to absorb a wide range of the solar spectrum, enhancing performance under different light conditions.

These advantages have maintained perovskite solar cells' status as a focus for researchers, investors, and industries. They present benefits that traditional solar cell technologies may not match. Their potential impact is significant in light of reductions in production costs and applications of cells across diverse scenarios.

Major Challenges in Scaling Up Perovskite Solar Cells

Despite these promising advantages, scaling up perovskite solar cells for mass market use faces numerous challenges.

•         Stability and Durability: One of the most prominent challenges is that, under environmental stress, perovskite solar cells degrade. Exposure to moisture, high temperatures, and ultraviolet light can significantly shorten their lifespan. The degradation problem mirrors issues faced by many sensitive materials not yet matured for widespread production.

•         Lead Toxicity: The majority of perovskite solar cells contain lead, raising environmental concerns and posing risks should lead leak into ecosystems. The presence of lead necessitates heightened caution during production, operation, and eventual recycling of the cells.

•         Reproducibility and Uniformity: Creating large-area perovskite films of consistent quality presents challenges. In the laboratory, smaller devices yield promising results. However, when researchers attempt to fabricate larger, uniform films, defects and variations in performance often occur.

•         Manufacturing Challenges: Integrating perovskite solar cells into existing manufacturing lines is complex. The new techniques viable in laboratory settings must be adapted for industrial production. Ensuring consistent performance on a large scale remains a significant challenge for manufacturers.

These challenges elucidate why perovskite solar cells, despite their promise, have yet to achieve widespread commercial deployment. Each issue requires thorough research and testing prior to leaving laboratory settings.

Technological and Commercial Barriers

The pathway to mass-market adoption faces technical and market challenges.

• Limited progress on long-term operational stability: Although short-term laboratory performances are impressive, real-world installations necessitate solar cells that function effectively for decades. Considerable work remains to ensure long-term reliability.

• Issues with scaling up solution processing for large-area devices: Processes yielding high efficiency at small-scale levels do not readily scale to larger panels. This discrepancy constitutes a major barrier for businesses aiming for large-scale production.

• Large-scale production cost versus performance trade-off: Performance must be balanced against production cost. In practice, enhancements in stability and efficiency may involve increased expenses. This balance is critical in granting the cells a competitive edge over established technologies.

• Lack of infrastructure for commercialisation: A fully developed supply chain or production facility dedicated to these new solar cells has yet to be established. This gap impacts the pace at which the cells can be integrated into established solar markets. Industries and investors await a more robust demonstration of technological maturity.

These challenges reflect the cautious approach both academia and industry adopt in the commercialisation of perovskite solar cells. Progress must be gradual, managing each challenge carefully to build confidence in the technology.

Potential Solutions and Advances

There is no singular solution to the scaling-up issues confronting perovskite solar cells. Various improvements are actively pursued by researchers to address the challenges.

Techniques such as encapsulation and additives have been implemented to make the perovskite layer more resistant to moisture and temperature. For instance, protective films can shield the active layers from environmental stress.

• Non-toxic alternatives to lead-based perovskites: Research is ongoing to replace lead with less toxic elements. Early candidates are utilising tin or other metals. Overall, these second-generation alternatives must maintain high efficiency while substantially reducing environmental risks.

• Advances in printing technologies and scalable manufacturing techniques: New printing methods and roll-to-roll processes are being refined. Several pilot lines demonstrate that it is possible to print large-area devices with consistent performance.

• Hybrid perovskites and tandem solar cells: Utilising perovskites in conjunction with additional materials in a tandem configuration has the potential to deliver both stability and improved performance. Some prototype devices already demonstrate this can be achieved through a layered approach that combines the properties of different materials.

Research continues to progress, with each new study bringing perovskite solar cells closer to meeting both technical and commercial criteria. The work is knowledgeable and meticulous, balancing innovation with considerations of safety and cost. For more information on perovskite solar cells, please visit Stanford Advanced Materials (SAM).

Frequently Asked Questions

F: What is the main advantage of perovskite solar cells?

They possess the advantage of high efficiency and low cost, consequently finding applications across various fields.

F: What is the biggest challenge to scaling up their production?

Ensuring long-term stability and uniformity in large-area manufacturing remains one of the critical challenges.

F: Are there ways to reduce lead toxicity in perovskite cells?

Q: Yes, there is ongoing research into nontoxic alternatives and stabilization techniques to mitigate environmental risks.

Reference:

[1] Mahapatra, Apurba & Prochowicz, Daniel & Tavakoli, Mohammad & Trivedi, Suverna & Kumar, Pawan & Yadav, Pankaj. (2019). A Review on the Aspects of Additive Engineering in Perovskite Solar Cells. Journal of Materials Chemistry A. 8. 10.1039/C9TA07657C.