Vikrant Sista Roll No: EE10S012 IR and UV solar cells for windows and energy scavenging applications

Sources Richard R Lunt and Valdamir Bulovic, “Transparent, near-infrared organic photovoltaic solar cells for window and energy-scavenging applications,” Appl. Phys. Lett. 98, (2011) Man Gu Kang et.al., “ Manufacturing method for transparent electric windows using dye-sensitized TiO2 solar cells,” Sol. Energ. Mat. Sol. C., 75, 475 (2003)

Outline Motivation Introduction IR solar sell device and performance UV solar cell device and performance Summary

Motivation Reflective or tinted windows used in automobiles and buildings Using low cost transparent PV technology the reflected ight will be used for energy generation Absorbing UV and IR and transmitting visible allows for lighting Combined advantage of power generation,lighting and temperature control

IR Solar cell Hetero Junction PV Chloroaluminumpentac ene (molecular donor) C 60 (molecular acceptor) BBAR – Broadband Antireflection coating DBR – Distributed Bragg Reflector(stop band 800nm)

IR Solar Cell Fabrication Glass substrate coated with ITO Thermal evaporation of MoO 3,ClAlPc,C 60,BCP RF sputtering of ITO directly on BCP DBR sputtered separately on quarts substrate BBAR precoated on quartz substrate and attached to glass substrate using index matching fluid

IR Solar Cell: Performance Efficiency(Open Diamond) Average Visual Transmission(Open Star) Open Circuit Voltage(triangles) Fill-Factor(square) Short Circuit Current(circle)

IR Solar Cell: Performance Transmission spectra of the OPV device for various ITO thickness and with and without NIR mirror

IR Solar Cell: Performance Picture (a) without the transparent OPV Picture (b) with OPV Picture (a) shows the OPV region overlaid on it with orange boxed showing active area A series integrated OPV powering a LCD clock

UV solar cells UV solar cells are not a major focus for energy scavenging applications as not much UV reaches surface But solar cells are still developed which absorb in UV range Three approaches exist Shift UV to another region and then use in a regular solar cell(Turbo Solar) Harness using GaN doped with Magnesium Dye N719

UV Solar Cell Dye +TiO2 active region Dye (N719) used for UV absorption Exposure to light excites the dye and electron injected into the TiO 2 Dye then absorbs electron form Pt/electrolyte

UV Solar Cell: Fabrication TiO2 colloid made into slurry and coated on glass substrate with ITO coated Substrate then immersed in solution with N719 dye for 24 hours to sensitize it Platinum electrode formed by spreading hexachloroplatanic acid over glass substrate and heating Iodide electrolyte introduced through the holes in platinum electrode glass Finally the two substrates are sealed using surlyn Holes in the glass substrate covered using surlyn and glass

UV Solar cell: Performance UV to visible absorption of N719 dye

Prototype of the designed Window

UV Solar cell: Performance Average Visible transmittance is 60% The solar cell has a Voc of 0.64V and J sc of 250mA and area of each solar cell is 64cm 2 Series connection of 9 such solar cell gives a open circuit voltage of 5.7V and a J sc of 220mA at one sun condition

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