Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Heat Transfer in Thin Films Thomas Prevenslik Berlin, Germany Hong Kong, China 1

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Background Over the past 30 years, heat transfer in thin films has been based on classical methods. However, for films less than about 100 nm, classical heat transfer cannot explain the reduced thermal conductivity found in experiments. 2

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Experiment 3 Pulse Method (Thin Solid Films, Kelemen, 36 (1976) ) Thermal Diffusivity K = thermal conductivity  = density, c = specific heat X1X1 X2X2 T1T1 T2T2 Wire FF Data Shows K  0 as   0 Substrate Film Problem Diffusivity  diverges as c  0 Can conductivity K be measured by Pulse Method? SS W

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Current Approach To explain reduced conductivity data, Fourier heat conduction theory is thought not applicable to thin films having thickness smaller than the mean free paths of phonons. Heat Transfer in thin films is modified to treat phonons as particles in the Boltzmann Transport Equation (BTE). 4

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Experiment and BTE Theory Bulk Copper 5

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Purpose 6 To provide a QM explanation for thin film heat transfer based on QED induced EM radiation using Standard Mixing Rules. QM = Quantum Mechanics QED = Quantum Electro Dynamics EM = Electromagnetic

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico QED induced EM radiation Classically, heat is conserved by an increase in temperature. But at the nanoscale, QM forbids heat to be conserved by an increase in temperature because specific heat vanishes. QED allows heat to be conserved at the nanoscale by the emission of nonthermal EM radiation 7

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Nanoparticle or Quantum Dot 8 NP, QD Molecular Collisions No Temperature change EM Emission Laser Radiation

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Thin Film 9 QED Heat Transfer Q Cond = Q Joule -Q QED Standard Mixing Rules  eff = K eff /  eff c eff c eff = c S and c F = 0  eff =(  F K F +  S K S )[(  F /  S )+1]/[c S (  F  F +  S  S ] K F =  eff c S [  F +  S (  S /  F )] - (  S /  F )K S K F ~ K Bulk Q QED Q Cond T1T1 T2T2 Current Approach Q Cond =Q Joule Kelemen K F = K S [(  F+S /  S )-1  S   F  K F << K Bulk Q Joule x 2 -x 1

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico EM Confinement For  << W and L,  2  n r Photons in Rectangular cavity resonator, n r > 1 10

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Specific Heat Thin films cannot conserve the Joule heat by an increase in temperature because specific heat vanishes Specific heat by Debye/Einstein Model for atomic vibration gives slow phonon (ps) response. Excitons in QDs produced promptly (fs). Modify Einstein Model for atom vibration to photon vibration inside the thin film. 11

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico QM Restrictions 12 Film Free Molecule

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Thin Film as an Einstein Solid N A = Number of Atoms in Film 3 N A Degrees of Freedom 13

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Einstein Specific Heat 14 Einstein Debye & Einstein

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Thin Film Specific Heat 15 3 microns

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico QED Induced Heat Transfer 16 Non Thermal Emission E P = Photon Planck Energy dN P /dt = Photon Rate

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Conductivity – Response Kelemen Copper Film Glass Substrate Mixing Rule Substrate Experiment

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico QED induced Heat Transfer 18

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico QED induced Heat Transfer 19

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico UV Laser Emission Zinc Oxide Sapphire He-Cd Laser 325 nm QED radiation ~ 388 nm  ~ 388/2(2.03 ) = 95 nm  < 100 nm Mat. Sci. Eng. B56 (1998) (QED cavity by Refractive Indices-Not Film Conductivity ) 20 Q Laser ~ Q QED Q Cond ~ 0

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Conclusions Thin film specific heat vanishes. Transient film temperatures follow the substrate allowed by QM to have specific heat. Bulk conductivity is maintained in the film, but there is no conductive heat loss parallel to the surface. The film loses heat normal to the surface by EM emission. Pulse Method requires modification using Standard Mixing Rules to measure thin film thermal conductivity QED induced EM emission can and should be measured with standard photomultipliers for 100 nm films. 21

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Extensions Nanocatalysts Surface Chemical Reactions 22

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Nanocatalysts Unsupported Supported 23

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Surface Chemical Reactions 24 “God made solids, but surfaces are the work of the Devil.” W. Pauli ( )

Third Int. Conf. Quantum, Nano, and Micro Tech. (ICQNM 2009) February 1-6, 2009 — Cancun, Mexico Questions & Papers