A New Energy Approach for a Sustainable and Comfortable Future

ST-OPV is a next-generation, film-based solar technology that simultaneously delivers power generation and heat shielding.

Its lightweight and flexible structure enables installation on windows, building exteriors, and mobility surfaces where conventional solar systems cannot be deployed. By expanding the range of viable applications, ST-OPV transforms architecture and urban space into distributed energy infrastructure, contributing to decarbonization and enhanced energy independence.

Technology

ST-OPV is a next-generation, film-based solar technology that simultaneously delivers power generation and heat shielding.

Its lightweight and flexible structure enables installation on windows, building exteriors, and mobility surfaces where conventional solar systems cannot be deployed. By expanding the range of viable applications, ST-OPV transforms architecture and urban space into distributed energy infrastructure, contributing to decarbonization and enhanced energy independence.

What is ST-OPV?

ST-OPV is a multilayer thin-film photovoltaic device based on organic semiconductor materials. A photoactive layer absorbs light and converts it into electrical energy within a compact layered structure.

Engineered as a lightweight, flexible film, ST-OPV can be integrated directly into architectural and mobility surfaces, enabling power generation in applications where conventional solar panels are impractical.

Close-up of ST-OPV organic thin-film solar cell, showing its translucent multilayer structure
ST-OPV film-type solar cell rolled into a cylindrical shape, demonstrating its flexibility and bendability

Technology Comparison

ST-OPV expands the range of surfaces capable of generating energy, extending solar functionality into applications conventional systems cannot efficiently serve. Rather than replacing established technologies, it broadens the solar ecosystem through architectural and structural integration.

PHD Printed Film

Silicon PV (c-Si)

Process temperature

Low (<120°C) ✓

High (~700°C) ✗

Emissions

Extremely Low ✓

High ✗

Substrate

PET-based ✓

Glass based ✗

Flexibility

30,000 cycles(1) ✓

Rigid and fragile ✗

Transparency (%)

Up to 50% ✓

0% ✗

Aesthetics

Multiple colors ✓

Dark blue ✗

Weight (per sqm)

Ultra-light (<0.5 kg) ✓

Heavy (~20.0 kg) ✗

Supply chain

Diversified (carbon/polymer) ✓

Concentrated (crystal silicon) ✗

Logistics (Watts per 20-ft container)(2)

2.5 MW ✓

0.13 MW ✗

PCE Efficiency (Watts per sqm)(3)

150W rapidly increasing ⏱

Up to 230W ✓

(1) Bending testing under 5 cm diameter roll                         

(2) PHD Printed [50 W / 0.5 Kg] per sqm VS. PHD Printed [Silicon PV / 20.0 Kg]                     

(3) Power conversion efficiency (PCE) / Measurement in scale-up device size  (Basu et al.,  Joule 8, 970-978 (2024)              

Foundations of OPV

Rooted in Nobel Prize–Recognized Japanese Scientific Breakthroughs

 

OPV traces its origins to two Nobel Prize–winning discoveries that advanced organic semiconductor technology.
The discovery of conductive polymers demonstrated that organic materials can conduct electricity, establishing the foundation of organic electronic materials. The development of cross-coupling reactions enabled the precise design of high-performance functional molecules, including conductive polymers.
The accumulation of this foundational science ultimately made possible the development of OPV as a new class of power-generation technology.

| Discovery of Conductive Polymers

 

Nobel Prize in Chemistry, 2000

Dr. Hideki Shirakawa

 

The discovery that organic polymers can conduct electricity established the field of organic semiconductors, enabling plastics and carbon-based materials to function as electronic devices.

| Suzuki–Miyaura Cross-Coupling Reaction


Nobel Prize in Chemistry, 2010
Dr. Akira Suzuki

 

Precision organic synthesis techniques enabled the controlled design of conjugated molecular structures, forming the basis for high-performance organic semiconductor materials.

- From Conductive Polymers to Organic Semiconductors -

Evolution of OPV Materials Enabled by Cross-Coupling Technology

Chemical structure of polyacetylene

polyacetylene

【1970s -】

 

  • Discovery of Conductive Polymers
  • Metallic conductivity by doping

 

 

 

Chemical structure of poly(p-phenylene vinylene) derivative

Poly(p-phenylene vinylene) derivatives

【1980s – 90s 】

  • Semiconducting and light-emitting properties
  • Used as emissive materials in OLEDs

 

Chemical structure of polythiophene derivative

polythiophene derivatives

【1990s – early 2000s】

 

  • Soluble in organic solvents
  • Standard material for OPV

 

 

 

Chemical structure of donor-acceptor type π-conjugated material

Donor-Acceptor type π-conjugated materials

【Late 2000s – present 

  • Bandgap engineering
  • Precise control of HOMO/LUMO energy levels

Advancement of π-conjugated materials enabled by cross-coupling

ST-OPV Strengths

Engineered for real-world integration, ST-OPV delivers a unique combination of safety, design flexibility, structural lightness, and thermal performance, expanding where and how solar can be deployed.

Icon representing organic material safety

 

Organic Materials and Safety

Based on organic semiconductor materials, ST-OPV is a lightweight, low-risk photovoltaic film for safe integration into buildings and infrastructure.

Icon representing high transparency and design versatility

High Transparency and Design Integration

Semi-transparent and color-tunable, ST-OPV integrates into glazing and facades without compromising architectural intent.

Icon representing ultra-lightweight and flexible installation

 

Lightweight and Flexible

Ultra-lightweight thin-film construction enables flexible handling and installation on load-sensitive or retrofit surfaces.

Icon representing energy-saving performance through heat-shielding effect

 

Heat-Shielding

Infrared absorption and reflection reduce heat gain while generating electricity, improving comfort and energy efficiency.

ST-OPV Social Value

| Integrated Power and Thermal Performance

Generates on-site electricity while reducing solar heat gain, improving overall building energy efficiency and operational performance.

| Distributed Energy for Infrastructure Resilience

Enables decentralized power generation across buildings and regions, strengthening energy security and enhancing resilience against disruption.

| Next-Generation Decarbonization Solutions

Advances decarbonization and responsible corporate management through renewable energy integrated directly into buildings.

| Aesthetic Energy Infrastructure Integration

Transforms built assets into power-generating infrastructure without sacrificing design integrity, landscape quality, or urban aesthetics.

Integrated Energy Solutions

ST-OPV expands where and how solar can be deployed. It enables integrated power generation across real-world assets while enhancing performance, efficiency, and sustainability.

 

Flexible Deployment

 

Unlock on-site power generation across glazing, facades, and load-sensitive structures where conventional solar cannot be installed.

 

Total Energy Cost Optimization

 

Generate electricity while reducing solar heat gain, improving overall building energy performance and long-term operating costs.

 

Environmental Value

 

Transform building exteriors into decarbonization assets that demonstrate responsible management while enhancing brand value and stakeholder trust.

 

Daylight with Thermal Control

 

Maintain natural light while controlling heat transmission, supporting occupant comfort, and reducing HVAC demand.

 

Seamless Synergy of Design and Energy

 

Integrate renewable energy without compromising design intent, aesthetics, or urban landscape quality.

 

Lower-Impact Materials Approach

 

Leverage organic semiconductor film technology designed for lightweight deployment and reduced environmental burden.

Applications

ST-OPV is designed for integration across diverse built environments and mobility platforms. Its lightweight, semi-transparent film format enables new energy-generating surfaces in commercial, public, and transportation sectors.

Commercial and Public Facilities

 

ST-OPV enables on-site power generation across retail, office, logistics, healthcare, and public buildings. Integrated into glazing and facade surfaces, it supports energy cost reduction and visible ESG initiatives without major structural modification.

Interior of a large commercial facility with atrium and glass ceiling, illustrating ST-OPV installation

Architecture and Building Materials

 

Applied to curtain walls, skylights, and building envelopes, ST-OPV transforms architectural surfaces into functional energy assets. Its transparency and flexibility allow renewable energy integration without compromising design intent.

Exterior of an office building with glass curtain wall and street trees, illustrating ST-OPV integration into building facades

Mobility

 

ST-OPV supports distributed energy functionality in mobility applications where weight, curvature, and design constraints limit conventional solar use. Its thin-film structure enables practical integration into next-generation transportation platforms.

Large trucks driving on a highway, illustrating ST-OPV integration into mobility and vehicle applications

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