Physicists Control Electrons at Femtosecond Timescales

January 22, 2016 | MIT

Estimated reading time: 3 minutes

“Say you tell me, ‘I’d like to have these electrons jumping from one layer to another, and I only have blue photons,’” Jarillo-Herrero says. “I can say that at least with blue photons, you have to apply this voltage. If you only have green photons, then you should apply more voltage than this. That’s what we’re able to map.”

Ultimately, he says these results may help to improve solar cells and energy harvesting devices by enabling them to capture and use more photo-excited electrons.

“Modern solar cells work such that if a photon comes and can be absorbed by silicon, it contributes to current in your photovoltaic device,” Jarillo-Herrero says. “If the light consists of lower-energy infrared photons, those are not absorbed by silicon. That limits seriously the efficiency of silicon solar cells. Now with our device, in principle you can absorb many lower-energy photons, those that silicon just lets through, such that the accumulation of that energy can contribute to a current in your electrical circuit. This is a mechanism by which you could think of doing it.”

Page 3 of 3

Share on:

Stay ahead of the technologies shaping the future of electronics with our latest newsletter, Advanced Electronics Packaging Digest. Get expert insights on advanced packaging, materials, and system-level innovation, delivered straight to your inbox.

Subscribe now to stay informed, competitive, and connected.

Suggested Items

Enabling the Interconnect Technologies That Transform Our World: MKS’ Strategic Role in Powering the Future of AI and HPC

10/20/2026 | John T.C. Lee, with Won Lee, Marc Tricard, and Kuldip Johal
AI is reshaping industries, economies, and daily life at an unprecedented speed. From generative AI and autonomous systems to high-performance computing (HPC) applications in science, defense, and advanced manufacturing, the demand for computational power is accelerating exponentially. But while algorithms capture the spotlight, the true enabler of this transformation lies deeper, in the physical infrastructure that makes AI possible. Performance in the AI era is no longer defined by transistor shrink alone. It is increasingly defined by how efficient systems are integrated, interconnected, cooled, and manufactured at scale.

A Real Look at Today's PCB Design With Stephen Chavez

10/13/2026 | Marcy LaRont, I-Connect007
What does it take to become a better PCB designer? At PCB West, I-Connect007’s Marcy LaRont talks with Stephen Chavez of Siemens and PCEA about the practical skills engineers need beyond traditional education. Chavez explains why mastering design tools, understanding manufacturability, and involving fabrication teams early are essential to successful designs. He also discusses the value of mentorship, industry certification, and conferences, offering practical advice for engineers looking to strengthen their skills and advance their careers.

Fresh PCB Concepts: Managing PCB Trace Width and Spacing

09/22/2026 | Team NCAB -- Column: Fresh PCB Concepts
As a fabricator, I know that trace width and spacing are some of the first items reviewed when determining whether a PCB can be manufactured reliably. They may look like simple dimensions in the design data, but the ability to reproduce them consistently depends on several factors, such as the circuit's location, the copper weight used, the design density, and any additional plating requirements. These can all change what is realistically achievable.

FSQuality Circuits to Showcase Advanced PCB Manufacturing Capabilities at PCB West 2026

09/18/2026 | FSQuality Circuits
FSQuality Circuits (FQC), a leading Thailand-based manufacturer of advanced printed circuit boards, will exhibit at PCB West 2026, taking place September 29 through October 2 at the Santa Clara Convention Center in Santa Clara, California.

Designers Notebook: Implementing Strategic Planning Principles for PCB Design

09/03/2026 | Vern Solberg -- Column: Designer's Notebook
Developing multiple-processor system-level products involves a broad range of engineering disciplines (commonly referred to as co-design), often led by a designated program manager who divides the development program into technical disciplines. The primary member of this team is the electrical engineer (EE), who prepares the overall schematic diagram of the product. This effort includes simulation and modeling, developing a BOM, and defining all active components and any specialized passive elements (often stipulating preferred or prequalified sources).

News Highlights

More News

Featured Books

Article Highlights

More Articles

Latest Columns

See all of our columnists

Media Kit - Choose Your Primary Marketing Focus: