Si nanopar tic le s: Ne w photonic and e le c tr onic mate r - PowerPoint PPT Presentation

Si nanopar tic le s: Ne w photonic and e le c tr onic mate r ial Dr. Munir H. Na yfe h De pa rtme nts o f Physic s, Unive rsity o f I llino is

NanoSi L e t the r e be L ight Natur e 2 2 Nano S i

F r om bulk to nanopar tic le s What make s silic on Glow? mission life time ~ ms) Dull I) Bulk Silic on ( E Diffic ult to c o nse rve mo me ntum in tra nsitio n a c ro ss • b a ndg a p. (I ndire c t g a p) Mo me ntum c a n c o me fro m c o upling to c rysta lline • pho no ns. (2 nd o rde r pro c e ss ) • nhanc e d life time ~ us) F luor e sc e nt II) Si Nanostr uc tur e > 3nm (E Quantum c o nfine me nt with b ulk-like e missio n • Mo me ntum c a n c o me fro m c o upling to c rysta lline • pho no ns 3.2eV Additio na l mo me ntum c a n c o me fro m b o unda ry • sc a tte ring o f e le c tro ns (dk dx la rg e r tha n 1). 1.1eV nhanc e d life time ~ ns) Glow III) Si nanopar tic le (1-3nm) ( E T ra pping o f e xc ito ns o nto a to mic intrinsic site s (Si-Si fo r • e xa mple ) whe re the c o nse rva tio n o f mo me ntum is lifte d. (dire c t g a p? ) Co mb ina tio n o f me c ha nisms S pac e c o nfine me nt • Mo le c ular c o nfine me nt S e lf-trappe d • Othe r ? • 3 3 Nano S i

Pr oc e ss and pur ific ation n i t e l l u B S R M E le c tr oc he mic al e tc h of bulk wafe r s 1-10 o hm-c m p-type <100> Si Curre nt c o nc e ntra te s a t me nisc us (~30mA/ c m2) Pa rtic le s dispe rse d in a so lve nt via so nic a tio n Pa rtic le s pro duc e d a re H-pa ssiva te d . ifie d b y size via g e l pe rme a tio n Par tic le s pur c hro ma to g ra phy; F ra c tio ns e xhib it diffe re nt lumine sc e nc e spe c tra Z. Yamani, H. Thompson, L. AbuHassan, and M. H. Nayfeh , Appl. Phys. Lett. 70 , 3404-3406 (1997) 4 4 Nano S i

Swe e t spots in Si c luste r size A family of magic size s o f hydro g e na te d Si na no pa rtic le s No magic size s > 20 a to ms fo r no n- hydro g e na te d c luste rs Materialstoday G. Belomoin, J. Therrien, A. Smith, S. Rao, S. Chaieb, M. H. Nayfeh, Appl. Phys. Lett. 80, 841 (2002) 5 5 Nano S i

Size -c olor -bandgap MRS Bulletin 1 nm 1.67 nm 2.9 nm 2.15 nm 10A Blue Green Red Yellow Eg = 3.5 /sqrt d Excitation at bandgap Z. Yamani, S. Ashhab, A. Nayfeh and M. H. Nayfeh, J. Appl. Phys. 83 , 3929-3931 (1998) 6 6 Nano S i

Silic on Nanopar tic le pr ototype (Quantum Monte Car lo simulation) I. Ide al bulk-like c onfigur ation (Band gap of 3.6-3.7 eV) •F ille d fulle re ne c o nfig ura tio n •T e tra he dra l Si c o re (5 a to ms) •24 hydro g e n pa ssiva te d c a g e •K no wn po sitio n o f Si a nd H 1 na no me te r •Hig hly rinc kle d (puc ke rre d b a ll) Si 29 H 24 (pe nta g o ns a nd he xa g o ns) 29 Silic o n (ye llo w) 1 Td atom and 28 atom fullerene cage 24 Hydro g e n (white ) L. Mitas, J. Therrien, R. Twesten, G. Belomoin, and M. H. Nayfeh, appl. Phys. Lett. 78, 1918 (2001) 7 7 Nano S i

Wide bandgap mate ial: Re c onstitution into films and solids (from Acetone) T he pa rtic le s a re ha rve ste d in a so lutio n. Pa rtic le s ma y the n b e pro c e sse d into a c e rta in a ssa y using : (from water) § Drying / e va po ra tio n § Spra y § Je t § E le c tro c he mic a l de po sitio n Pr oduc e s wide bandgap solids 8 8 Nano S i

F r om bulk band str uc tur e to mole c ular bands (E xc ite d state s of Si29) Bulk absorption Mole c ular -like e xc ite d state bands --- R ic har d Mar tin Excitation spectra (absorption x emission) Time dependent LDH theory Particle absorbtion & QMC S. Rao, J. Sutin, R. Clegg, E. Gratton, M. Nayfeh, S. Habbal, A. Tsolakidis, R. Martin, Phys. Rev. B (2004) 9 9 Nano S i

Single -E le c tr on T r ansistor s and Me mor y Ce lls A single -e le c tr on ansis-tor (SE T ) is a tr thre e -te rmina l de vic e , with g a te , so urc e , a nd dra in. Me mor y Nano- c e lls 10 10 Nano S i

Nano me mor y on a supe r c hip B l a c k ( 1 ) , R e d ( 2 ) , B l u e ( 3 ) , O r a n g e ( 5 ) , T u r q ( 8 ) , P u r p l e ( 1 0 ) 5 . 0 0 E- 10 4 . 5 0 E- 10 4 . 0 0 E- 10 Me tal-oxide -silic on (MOS) 3 . 5 0 E- 10 3 . 0 0 E- 10 2 . 5 0 E- 10 2 . 0 0 E- 10 1. 5 0 E- 10 Capac itor me mor y 1. 0 0 E- 10 5 . 0 0 E- 11 0 . 0 0 E+0 0 - 2 . 0 0 E+0 - 1. 9 0 E+0 - 1. 8 0 E+0 - 1. 7 0 E+0 - 1. 6 0 E+0 - 1. 5 0 E+0 - 1. 4 0 E+0 - 1. 3 0 E+0 - 1. 2 0 E+0 - 1. 10 E+0 0 - 1. 0 0 E+0 0 0 0 0 0 0 0 0 0 0 Contain unifor m 1 nm silic on nanopar tic le s 4.6E-1 0 4.1 E-1 0 3.6E-1 0 Capacitance (F) 3.1 E-1 0 Al electrode 2.6E-1 0 2.1 E-1 0 top oxide 1 .6E-1 0 nanoparticles 1 .1 E-1 0 +/- 6.0E-1 1 tunnel oxide 1 .0E-1 1 p-Si substrate -5 -4 -3 -2 -1 0 1 2 Gate Voltage (V) Al electrode 11 11 Nano S i

Ar omatic bi-linke r s Be nzoic Ac id, COOH Salic ylic Ac id, OH and COOH Butterfly conjugation T e r e pththalic Ac id, COOH and COOH Simulations: Structure, Optical properties Chemical activity Vibrations Anthr anilic Ac ids, COOH and NH2 12 12 Nano S i