Editing Diamondoid (section)

== Optical and electronic properties ==

The [[Absorption (electromagnetic radiation)|optical absorption]] for all diamondoids lies deep in the [[ultraviolet]] spectral region with optical [[band gap]]s around 6 [[electronvolt]]s and higher.<ref>{{cite journal |first1=L. |last1=Landt |first2=K. |last2=Klünder |first3=J. E. |last3=Dahl |first4=R. M. K. |last4=Carlson |first5=T. |last5=Möller |first6=C. |last6=Bostedt | title= Optical Response of Diamond Nanocrystals as a Function of Particle Size, Shape, and Symmetry | journal= Physical Review Letters | year= 2009 | volume= 103 |issue=4 | pages= 047402 |doi= 10.1103/PhysRevLett.103.047402 | bibcode=2009PhRvL.103d7402L | pmid=19659398|url=http://bib-pubdb1.desy.de/record/92624 }}</ref> The spectrum of each diamondoid is found to reflect its individual size, shape and [[molecular symmetry|symmetry]]. Due to their well-defined size and structure diamondoids also serve as a model system for electronic structure calculations.<ref>{{cite journal |first1=M. |last1=Vörös |first2=A. |last2=Gali | title= Optical absorption of diamond nanocrystals from ''ab initio'' density-functional calculations | journal= Physical Review B | year= 2009 | volume= 80 |issue=16 | pages= 161411 |doi= 10.1103/PhysRevB.80.161411|bibcode = 2009PhRvB..80p1411V }}</ref>

Many of the optoelectronic properties of diamondoids are determined by the difference in the nature of the [[HOMO/LUMO|highest occupied and lowest unoccupied molecular orbitals]]: the former is a [[bulk state]], whereas the latter is a [[surface state]]. As a result, the energy of the lowest unoccupied molecular orbital is roughly independent of the size of the diamondoid.<ref name="dmc_diamondoid">{{cite journal |first1=N. D. |last1=Drummond |first2=A. J. |last2=Williamson |first3=R. J. |last3=Needs |first4=G. |last4=Galli | title= Electron emission from diamondoids: a diffusion quantum Monte Carlo study | journal= Physical Review Letters | year= 2005 | volume= 95 |issue=9 | pages= 096801–096804 |doi= 10.1103/PhysRevLett.95.096801 | bibcode=2005PhRvL..95i6801D|arxiv = 0801.0381 | pmid=16197235|s2cid=16703233 }}</ref><ref>{{cite journal |first1=T. M. |last1=Willey |first2=C. |last2=Bostedt |first3=T. |last3=van Buuren |first4=J. E. |last4=Dahl |first5=S. G. |last5=Liu |first6=R. M. K. |last6=Carlson |first7=L. J. |last7=Terminello |first8=T. |last8=Möller | title= Molecular Limits to the Quantum Confinement Model in Diamond Clusters | journal= Physical Review Letters | year= 2005 | volume= 95 |issue=11 | pages= 113401–113404 |doi= 10.1103/PhysRevLett.95.113401 | bibcode=2005PhRvL..95k3401W | pmid=16197003|url=https://digital.library.unt.edu/ark:/67531/metadc876588/ |type=Submitted manuscript }}</ref>

Diamondoids have been found to exhibit a negative [[electron affinity]], making them potentially useful in [[Field electron emission|electron-emission]] devices.<ref name="dmc_diamondoid" /><ref>{{cite journal |first1=W. L. |last1=Yang |first2=J. D. |last2=Fabbri |first3=T. M. |last3=Willey |first4=J. R. I. |last4=Lee |first5=J. E. |last5=Dahl |first6=R. M. K. |last6=Carlson |first7=P. R. |last7=Schreiner |first8=A. A. |last8=Fokin |first9=B. A. |last9=Tkachenko |first10=N. A. |last10=Fokina |first11=W. |last11=Meevasana |first12=N. |last12=Mannella |first13=K. |last13=Tanaka |first14=X.-J. |last14=Zhou |first15=T. |last15=van Buuren |first16=M. A. |last16=Kelly |first17=Z. |last17=Hussain |first18=N. A. |last18=Melosh |first19=Z.-X. |last19=Shen | title= Monochromatic Electron Photoemission from Diamondoid Monolayers | journal= Science | year= 2007 | volume= 316 |issue=5830 | pages= 1460–1462 |doi= 10.1126/science.1141811 |pmid=17556579 |bibcode = 2007Sci...316.1460Y |url=https://cloudfront.escholarship.org/dist/prd/content/qt5h79b9nr/qt5h79b9nr.pdf |doi-access=free }}</ref>