Efficient hot-carrier dynamics in near-infrared photocatalytic metals

Efficient optical extraction of hot-carrier energy.

Light-induced generation of free charge carriers in semiconductors constitutes the physical basis of photodetection and photovoltaics. To maximize its efficiency, the energy of the photons must be entirely used for this purpose. This is highly challenging owing to the ultrafast thermalization of 'hot' carriers, which are created by absorption of high-energy photons. Thermalization leads to heat...

Near-infrared free carrier absorption in heavily doped silicon

Hot Carrier-Based Near-Field Thermophotovoltaic Energy Conversion.

Near-field thermophotovoltaics (NFTPV) is a promising approach for direct conversion of heat to electrical power. This technology relies on the drastic enhancement of radiative heat transfer (compared to conventional blackbody radiation) that occurs when objects at different temperatures are brought to deep subwavelength distances (typically <100 nm) from each other. Achieving such radiative he...

Ultrafast Hot Carrier Dynamics in Materials from Ab Initio Calculations

!!!!!How does an excited electron lose its energy? This problem is central in fields ranging from condensed matter physics to electrical engineering and energy. We developed and applied calculations to study the dynamics of out-of-equilibrium charge carriers – also known as hot carriers (HCs) – in semiconductors and metals [1–3]. We present ab initio calculations of electron-phonon, electron-el...

Energy flows in graphene: hot carrier dynamics and cooling.

Long lifetimes of hot carriers can lead to qualitatively new types of responses in materials. The magnitude and time scales for these responses reflect the mechanisms governing energy flows. We examine the microscopics of two processes which are key for energy transport, focusing on the unusual behavior arising due to graphene's unique combination of material properties. One is hot carrier gene...