Semiconductor (Quantum dots) sensitized solar cells . DSSC 的缺點. 染料 : dye 只能吸收一部分的太陽光譜 (dye:350-750 nm, 太陽光 350-2500 nm). 電解液 : 碘離子具腐蝕性 電解液 液體 怕漏 光電子會 recombination ，降低電池之電流及效率。. 染料為有機物 (organic) ，遇高溫會破壞 有機物長時間穩定性較差，壽命問題. Semiconductor 為無機物，熔點高，長期穩定 無機物比較不怕電解液腐蝕 - PowerPoint PPT Presentation
Semiconductor sensitized solar cells
Semiconductor (Quantum dots) sensitized solar cells DSSC
: dye (dye:350-750 nm, 350-2500 nm).: recombination
(organic) Semiconductor sensitizers Semiconductor semiconductor
Extremely thin absorber semiconductor sensitized solar cells
(-solid state)
Semiconductor absorber materials: PbS, CdSe, CdS, In2S3, Sb2S3,
Cu2-xSTernary semiconductors: CuInSe, AgSbS, AgBiS,.electron
conductor:TiO2hole conductor: CuSCN, PEDOT, spiro-ometadThickness
of semiconductor absorber: ~ several nm or 10 nm.A solid-state
solar cell.Efficiency 11%
Quantum-dot sensitized solar cellsWhat is a quantum dot: a
nanoparticle of diameter several nm to a few hundred nm.When
diameter ~ 10-20 nm, quantum effect occurs.Quantum dot
semiconductor materials: CdS, CdSe, CdTe, PbS, PbSe, InP, InAs,
Ag2S, Ag2Se, CuXS etc.
Advantages of QD-DSCs (tunable absorption bands)quantum size
effect (high extinction coefficients) (multiple electron-hole pair
generation)-e-h100% Quantum size effect QD radius decrease, energy
gap increase
e-h pairs
semiconductor quantum dots
CBD: chemical bath deposition SILAR (successive ionic layer
adsorption and reaction)Hydrothermal ()
Chemical bath depostion Cd+2S-2ion-by-ion
SILAR growth ()
SILAR
: CdS quantum dots
ethanolethanolCdSe QD SEM, AFM pictures
Ag2S QDs TEM image
Ag2S absorption spectra vs SILAR cycles
Dependence of I-V curves on radiation power for Ag2S solar
cellsSample no.ElectrodesJsc (mA cm-2)Voc (V)FF (%) (%)1Ag2Se
(2)9.280.2927.50.742Ag2Se (3)17.30.2622.31.013Ag2Se
(4)27.20.2622.31.574Ag2Se (5)24.40.2621.61.375Ag2Se
(4)/ZnS28.50.2723.81.766Ag2Se (4)/no Ti-iP18.30.2821.11.047Ag2Se
(4)/ZnS polysulfide33.30.1524.31.21Table 1. Photoelectrochemical
performance of Ag2Se-QD sensitized solar cells with different SILAR
cycles
Ternary QDs AgSbS2
X-ray, absorption,
IV curves vs SILAR
EQE curve
Sb2S3 solid state solar cell
light intensityJsc (mA/cm2)Voc (mV)ff (%)10%
sun1.515450.645.250% sun6.515940.524.0100% sun10.626100.483.1
Isc=17.8 mA/cm2, Voc=0.98V, Eff=10.9%,
SILAR
SILAR
