Maa nan Zaneen Photo Electrons?

Mai suna Photo Electrons?

Takaitaccen Photoelectron

Photoelectron shine elektron da aka fitar da shirin daga zafi a lokacin da ya ci gaba karshe. Wannan fitar da shi anaka suna photoelectric effect, wanda yake bayar da alama mai yawa don tsarin kwantum na karshe da mutane. Littafin yana bayyana cewa muna suna photoelectrons, tare da yadda ake bi su, abubuwa masu sauki da yadda ake fitar da su, da kuma yadda ake amfani da su a sayar da ilimi da fanni.

Photoelectric Effect

Photoelectric effect shine yanayin da elektron suka fitar da shirin daga zafi a lokacin da aka gaba karshe da adadin hali ko gaba karshe da ke kusa. Zafin yana iya zama metal, semiconductor, ko wani abu da elektron da ke kusa ko da ke kula da surface. Karshe yana iya zama visible, ultraviolet, ko X-ray, daya daga wannan da work function ta zafi.

Work function shine adadin gaba karshe da ke da kyau don ka fitar da elektron daga surface na zafi. Ana kunna shi a electron volts (eV), wanda yake nufin gaba karshe da elektron yake samu a lokacin da ya ci gaba daga potential difference na one-volt. Work function yana haɗa da nau'in zafi da kallo, kafin ya kawo ɗaya zuwa 6 eV don metals.

Idan karshe na frequency f ko wavelength λ ya ci surface na zafi, har photon (ko quantum na karshe) yana da gaba karshe E wanda aka bayar da

E=hf=λhc

ida h shine Planck’s constant (6.626 x 10^-34 J s), da c shine speed of light (3 x 10^8 m/s). Idan gaba karshe na photon E yana da yawan da kusa ko da work function W na zafi, akwai cewa photon yana iya ba su gaba karshe zuwa elektron a surface, da kuma elektron yana iya fitar da shi daga zafi da yawan kinetic energy K wanda aka bayar da

K=E−W=hf−W

Electron da suka fitar da hakan suna photoelectrons, da suke dogara photocurrent da ake iya bincika ta a lokacin da ake kasa zafi zuwa external circuit.

Work Function

Work function shine adadin gaba karshe da ke da kyau don ka fitar da elektron daga zafi, wanda yake haɗa da fitar da photoelectron.

Fitar Da Kyau

Fitar da photoelectrons shine fitar da kyau da ke da frequency na karshe, ba intensity.

Amfani

Photoelectric cells ko solar cells: Wadannan shine devices da suka haɗa kan gaba karshe na karshe zuwa gaba karshe na elektro da tunanin photoelectric effect. Suna da semiconductor material (masu ma'ana silicon) da suka ci gaba photons da suka fitar da photoelectrons, da kuma suka dogara electric current a lokacin da ake kasa su zuwa electrodes.

Photomultiplier tubes: Wadannan shine devices da suka haɗa kan signals na karshe da suka ci gaba karshe da tunanin series of electrodes da suka fitar da secondary electrons idan suka ci gaba photoelectrons. Ana amfani da su a detectors for radiation, spectroscopy, astronomy, da medical imaging.

Photoelectron spectroscopy:

Wannan shine technique da ake amfani da photoelectrons don bayyana chemical composition da electronic structure na materials. Yana haɗa da shining beam of photons (kamar X-rays ko UV light) a sample da kuma measuring kinetic energy da angular distribution na emitted photoelectrons. Daga bayanin conservation of energy principle, binding energy na photoelectrons zai iya tabbatar, wanda yake nuna energy levels na atoms da molecules a sample. Photoelectron spectroscopy zai iya bayyana valence da core electrons, molecular orbitals, chemical bonds, da surface properties na materials. Photoelectron spectroscopy ana amfani da shi a physics, chemistry, biology, da materials science.

Mukadimci

A cikin littafin, muna samun bayanin photoelectrons da amfani. Photoelectrons shine elektron da suka fitar da shirin daga zafi a lokacin da ya ci gaba karshe da adadin hali da ke kusa.

Yanayin fitar da photoelectrons anaka suna photoelectric effect, wanda yake bayar da alama mai yawa don tsarin kwantum na karshe da mutane. Photoelectric effect yana da wasu abubuwan da ke da frequency da intensity na karshe, work function na zafi, da kuma kinetic energy na photoelectron.

Photoelectrons zai iya amfani a bayyana electronic structure da chemical composition na materials da tunanin various techniques of photoelectron spectroscopy, kamar X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), angle-resolved photoelectron spectroscopy (ARPES), two-photon photoelectron spectroscopy (2PPE), da extreme-ultraviolet photoelectron spectroscopy (EUPS).

Photoelectron spectroscopy shine tool mai muhimmanci don fahimtar properties da interactions na atoms da molecules a different states of matter.