Tech Insights

A Solar Sandwich and 5 Other Developments for a Bright Future

April 17, 2024 by Jake Hertz

Six recent research developments are tackling the biggest challenges in solar power, including solar panel materials and construction.

Resolving numerous technical and manufacturing challenges is crucial for solar power's future expansion. Fortunately, research teams have been working on several fronts to advance photovoltaic (PV) technology. 

Recent worldwide research has focused on solar panel materials and construction, making strides in nanotechnology, cell structure, and materials, including perovskite. 


Flexible solar panel material using nanotubes.

Flexible solar panel material using nanotubes. Image used courtesy of University of Surrey


1. Surrey’s Bifacial Solar Panels

Researchers from the University of Surrey used nanotechnology to increase the efficiency of bifacial solar panels.

The team significantly enhanced the panels' efficiency using single-walled carbon nanotubes for front and back electrodes. These nanotubes, thinner than a strand of DNA, allow the panels to harvest sunlight from both sides, leading to higher energy generation. Remarkably, the back panel produces nearly as much power as the front, achieving more than 36 mW per square centimeter. 

This design reduces production costs by up to 70%, potentially enabling the solar energy market to make cheaper and more efficient solar power solutions.


2. Denmark’s Solar Sandwich

Researchers at the Technical University of Denmark have developed a novel solar cell structure termed the "solar sandwich" to enhance solar efficiency. 


Device architecture of the tandem cell.

Device architecture of the tandem cell. Image used courtesy of Nielsen et al.


This technology involves tandem solar cells integrating two absorbers with distinct bandgaps within a single device. This structure is significant because it can theoretically achieve higher device efficiencies than traditional single-junction PV technologies, which are nearing their efficiency limits. The researchers achieved a notable open-circuit voltage of 1.68 V and found a significant amount of the photovoltaic losses related to parasitic resistance, offering a path for future improvements. 


3. NREL Anticipates the Future

In its latest research, the National Renewable Energy Laboratory (NREL) examines future reliability issues in solar module technology. Part of the Durable Module Materials (DuraMAT) Consortium, the study recommends identifying the benefits and challenges of module materials and designs before they are widely deployed. 

The research specifically explores the future reliability challenges of PV modules amid technological advancements. It categorizes expected changes in crystalline-silicon module designs into four key areas: 

  • Module architecture
  • Interconnect technologies
  • Bifacial modules
  • Cell technology

The comprehensive analysis pinpoints 11 trends likely to influence near-term module designs. It also emphasizes the importance of accelerating the PV reliability learning cycle to enhance the assessment of emerging module products and designs. It advocates for continued monitoring of technological trends and their implications for module reliability.


4. High-Efficiency Flexible Cells

Researchers from Tsinghua University have achieved a breakthrough in flexible perovskite solar cell (FPSC) efficiency using a novel fabrication technique. 


The tin precursor helped the cells achieve a power conversion efficiency of up to 25.09 percent

The tin precursor helped the cells achieve a power conversion efficiency of up to 25.09%. Image used courtesy of the authors


Using a chemical bath deposition method with tin sulfate as a precursor, they developed tin oxide as an electron transport layer without requiring strong acids. This technique improved the power conversion efficiency of their cells to a record 25.09% while also enhancing the durability and high-temperature stability of the cells. Specifically, the cells were shown to maintain 90% of their power conversion efficiency even after the cells were bent 10,000 times. 

The team anticipates this advancement paving the way for FPSCs' broader applications, including aerospace and flexible electronics.


5. Next-Gen Perovskite Manufacturing

At the University of Colorado Boulder, researchers made significant strides in developing next-generation perovskite solar cells.

Addressing the challenge of coating the semiconductor onto glass plates for commercial-scale production, the team discovered that adding dimethylammonium formate to the perovskite solution prevents oxidation, enabling ambient air coating. This innovation leads to nearly 25% efficiency in perovskite cells, with improved stability and the potential for tandem cells that exceed 50% efficiency with the operational lifetime of conventional silicon panels. 


6. Additives for Improved Efficiency and Stability

Researchers at the Ningbo Institute of Materials Technology and Engineering have developed a multifunctional additive to significantly boost the efficiency and stability of inverted perovskite solar cells (PSCs). 


Power conversion efficiency of the inverted PSCs

Power conversion efficiency of the inverted PSCs. Image used courtesy of Ningo Institute of Materials Technology and Engineering


By incorporating potassium (4-tert-butoxycarbonylpiperazin-1-yl) methyl trifluoroborate (PTFBK) into the perovskite precursor solution, the team could enhance carrier extraction and passivate defects in the perovskite films. This approach led to high-quality perovskite films, resulting in rigid and flexible p-i-n PSCs with 24.99% and 23.48% power conversion efficiencies, respectively. The PTFBK-modified devices also demonstrated exceptional stability under various stress conditions, including heat, humidity, and continuous illumination.


A Brighter Future

The future of a sustainable society will hinge largely on solar panel performance. These six studies, each pushing the industry's state forward in some capacity, make it clear that the impetus for change is understood, and the industry is taking necessary action.