Are Substitutes to Cd-Based Quantum Dots in Displays More Sustainable, Effective, and Cost Competitive? An Alternatives Assessment Approach

Abstract

Light emissive organics and inorganic nanoparticles are substance classes competing for applications in displays in the form of organic light emitting diodes (OLEDs) and quantum LEDs (QLEDs), respectively. Upcoming substance classes, perovskites and Q-OLED displays, also contain novel nanomaterials and organics for these applications. However, the safety and viability of these emissive substances is difficult to assess quickly and broadly because of their complexity, their inherently different structures, and their rapid evolution in the literature. We propose the use of an alternatives assessment focusing on hazard, cost, and performance, so as to compare these possible substitute substances, with incombent cadmium-containing quantum dots. This assessment type is used in industry and government to inform chemical substitution. It uses available information, while pointing out important data gaps for decision-making. The cost assessment highlights competitiveness of OLEDs because of the low amounts needed in their application for display, but performance assessments do not identify a preferred alternative. The hazard results indicate that there is no clear alternative either, with each novel nanomaterial or organic substance having different negative aspects. These results identify the need for a low-hazard highperforming alternative substance, and the assessment provides a framework for researchers to evaluate their own novel substances.

Helping Incorporate Safe and Sustainability into Materials Research: A Checklist Tool Designed for Early Career Researchers

“…Consideration of such hazard, economic, and regulatory data is necessary to meet certain principles of SDGs, green chemistry, planetary boundaries, and essential use, although these assessments also introduce complexities into a project and may require more expertise and resources. Tools such as an alternatives assessment framework may be helpful here as it is a process for identifying, comparing, and selecting safer alternatives to chemicals of concern (including those in materials, processes, or technologies) based on their hazards, performances, and economic viabilities. − Depending on the use case, other assessment approaches exist (e.g., cost-benefit analysis, ecosystem services valuation, risk assessments). Social life cycle assessments have also evolved to document the human impact of technologies, which relates to 14 out of the 17 SDGs .…”

Highly Stable Bio-templated InP/ZnSe/ZnS Quantum Dots for Specific Monitoring of Bacterial Membrane Proteins

“…On the other hand, carbon-based QDs are the second largest group of established nanomaterials that have been proposed for various biomedical applications 11,12 . Although they possess superior photoluminescent properties, heavy-metal and carbon-based QDs disappoint when assessed for toxicity (e.g., cytotoxicity, environmental damage), cost, and performance 13,14 . Because of the dangers of heavy metal exposure and photodegradationinduced cytotoxicity of carbon-based QDs, many concerns have been raised regarding their environmental, human health, and physical property considerations 14 .…”