Elektronika Organik

Eka Maulana, ST., MT., MEng.

Teknik ElektroUniversitas Brawijaya

#4 Solar Sel Organik - DSSC (Dye-Sensitized Solar Cell)

Senin, 18 Maret 2013

DSSC

2DSSC| Elektonika Organik

Efisiensi Konversi

3DSSC| Elektonika Organik

(Crabtree & Lewis, 2007)

Efisiensi Tipical current photovoltaic

Type EfficiencySingle crystal Si 20%Thin film Si ~10%Amorphous Si ≤10%CdTe 16%GaAs Multilayers ~25% or more Polymer PV ~2-8%Gratzel Liquid Electrolyte ~10%Gratzel Polymer Glass ~5%

4DSSC| Elektonika Organik

Analogi Fotosintesis

5DSSC| Elektonika Organik

Fotosintesis vs Solar Sel

6DSSC| Elektonika Organik

Struktur Dasar DSSC

Bagian BAWAH(KATODA)Bagian ATAS

(ANODA)

TCO(ITO)

DYE

Elek

trol

itCounter Elektroda

(Pt/C)

FOTON

KacaKaca

7DSSC| Elektonika Organik

Gratzel Cell: mimic fotosintesis

Performansi awal 10% (efisiensi cahaya menjadi listrik), dan estimasi biaya 1/4 dari PV konvensional.

8DSSC| Elektonika Organik

Cara Kerja

9DSSC| Elektonika Organik

Mekanisme: Prinsip operasi DSSC

4

1

2

3

5

10DSSC| Elektonika Organik

ElektrolitDiffusion Rate

Redox PotentialAdditives

Degree of Oxidation

RangkaianBlocking Layers

Electrocatalytic Deposits

DyeAbsorption Band

Blocking Efficiency

Material Semikonduktor

Band GapDefects

Surface Area

Parameter Optimasi

11DSSC| Elektonika Organik

Persamaan Reaksi Deskripsi

Dye excitation

Dye relaxation

Dye regeneration

Electron injection

Dye recombination

Electrolyte recombination

Current collection

Electrolyte reduction

Reaksi DSSC

2

* *2TiOS e TiO S

*hS E S

S A S A

2

* *2 TiOS TiO e S

2

*TiOe A A

2

*TiO Ie FTO e

Ie A A

*hE S S

12DSSC| Elektonika Organik

Kinetik

5

1

2

3

4

Dye Excitation

Electron Injection

Current Collection

Dye Regeneration

Electrolyte Reduction

* *r k photon

* * 3r k dye k dye electrolyte

2

*cb cb TiOr k e Orbital

cb dyer k

13DSSC| Elektonika Organik

Antarmuka

14DSSC| Elektonika Organik

Analisis DSSCPhysical and Chemical Properties

Cell Performance

Property Method(s)

Absorption Band Absorption Spectra

Redox Potential Stationary Amperometry

Diffusion Coefficient (electrolyte) Fixed potential 2-electrode cell

Structure NMRX-ray diffractionElemental Analysis

Properties Method(s)

Electron LifetimesDiffusion Coefficients

Light-induced photocurrent/voltage transients

Open circuit electron density Charge extraction

Cell capacitance Laser pulse over illumination

15DSSC| Elektonika Organik

Tested Organic Dyes

NKX2587 (n=1)NKX2697 (n=3)

MK1: (R=C6H13) n=3MK2: (R=C6H13) n=4MK3: (R=H) n=3MK11: (R=C6H13) n=5

D77

D149

16DSSC| Elektonika Organik

Ruthenium Dyes

17DSSC| Elektonika Organik

Organik vs. Ruthenium

Organic Dyes:

Ruthenium complexes:Have a large absorption bandProduce the best solar cell efficiency (currently)

Have better extinction coefficientsAllow more variations in structure and colorCost much less

18DSSC| Elektonika Organik

ODSC Results

All showed lower VOC, and higher JSC, slightly higher D and lower τ

τ is proportional to molecular size (Coumarine/Indoline dyes)

Carbazole dyes showed longer τ with increased alkyl chains

Smaller dye molecules need higher [I-] (slower reduction kinetics)

Do not block as well and may create positive TiO2 surface charge

Organic dyes may complex with triiodide to impede redox current

Size Matters (?)

Charge More

Organics show aggregation on the TiO2 surface

19DSSC| Elektonika Organik

Elektrolit

3 2 3I e I

33 2I e I

( ) ( )4 42 2 2 2

III IICo dbbip ClO e Co dbbip ClO

( ) ( )4 42 2 2 2

II IIICo dbbip ClO Co dbbip ClO e

(dbbip) = 2,6-bis(1’-butylbenzimidazol-2’-yl)pyridine

20DSSC| Elektonika Organik

Iodine vs. Cobalt

Iodide/Triiodide:

Co(II)/Co(III) complexes:

Minimal absorption in desired region of spectrum

Outer shell electron transfer (minimal reorganization)

Absorbs in visible region of spectrum

Aggressively attacks silver current collectors

Low redox potential limits open circuit voltage

Single electron transfer

21DSSC| Elektonika Organik

Cell Optimization ResultsSensitizer

Less negative charges increases performanceSmaller dye allows electrolyte to form ion pairs or steal conduction electron

Photoanode (TiO2)Photocurrent decreases with increasing thickness of layersElectrolyte is reduced at TCO without good blocking layerCounterelectrode is not efficient without electrocatalytic platinum deposit

Current density decreases when degree of oxidation exceeds 11%

Redox Efficiency

Counterelectrode illumination is better when mass transport is limiting

Additives

TPB passivates recombina on centers (photovoltage ↑ by 100mV at 100W/m2)LiClO4 creates positive charge on TiO2 (photocurrent ↑ 2x at 100 W/m2)

22DSSC| Elektonika Organik

Tugas I

http://ieeexplore.ieee.org

Keyword: DSSC, dye, Organic PV (/sejenisnya)*masing-masing orang minimal 5 jurnal

Hingga tanggal 8 april 2013 (softcopy [pdf] via email)

23DSSC| Elektonika Organik

Review Journal-Jurnal Elsevier (individu)Hasil Review (softcopy/doc) 1 Aril 2013

Cetak Jurnal aslinya (hardcopy/A4) 1 April 2013Presentasi (softcopy/ppt) mulai 8 April 2013

Tugas II