High efficiency CZTSSe solar cells enabled by dual Ag-passivation approach via aqueous solution process

Impact of Chemical Source Selection on Aqueous Spray-Deposited CZTSSe Solar Cells

“…In addition to the E U characterization, we estimated potential fluctuations (γ opt ) using the Shklovskii and Efros model. , As depicted in Figure d, our analysis revealed γ opt values of 57.1, 54.0, and 53.2 meV for CZTSSe-A, CZTSSe-N, and CZTSSe-C solar cells, respectively. The higher γ opt value observed in the CZTSSe-A solar cell can be attributed to an increased number of recombination losses, which is consistent with the E U trend.…”

Efficiency Improvement of Narrow Band Gap Cu(In,Ga)(S,Se)2 Solar Cell with Alkali Treatment via Aqueous Spray Pyrolysis Deposition

“…This downshift in CBM leads to an increase in spike-type conduction band offset (CBO). When the CBO is larger in spike-type configuration, the device exhibits a red kink in the JV curve. , We measured JVT curves for the three devices, and the results are displayed in Figure S8, where JV curves are measured under various conditions: dark, white light illumination, red-filtered illumination with long-pass filter at 665 nm, and yellow-filtered illumination with long-pass filter at 500 nm at 300 and 240 K. The Rb-CIGSSe and Cs-CIGSSe devices exhibit a red kink in the JV curves measured at 240 K, while the CIGSSe device showed no noticeable red kink compared to the other devices. This JV result supports an increase of CBO via the downshift of the CBM in the Rb-CIGSSe and Cs-CIGSSe cells, as shown in Figure .…”

“…The full device structure was then completed with the deposition of i-ZnO (∼50 nm) and tin-doped indium oxide (ITO) (∼300 nm) layers by radio frequency (RF) magnetron sputtering. Detailed information on the buffer and window layer fabrication processes can be found elsewhere. ,,− No additional antireflection coatings were applied to the fabricated devices. For measurement of device performance, we mechanically scribed the cell with an area of 0.20 cm 2 .…”

“…With air annealing, they obtained improved crystallinity of the CISSe absorber without carbon residue near the bottom electrode, which enabled a PCE of more than ∼14%. But, all device parameters, V oc , short-circuit current density ( J sc ), and fill factor ( FF ), were lower compared to the devices made by using a vacuum-based process. ,, We have developed spray pyrolysis with deionized water (DIW) for Cu­(In,Ga)­(S,Se) 2 (CIGSSe) solar cells. ,,− DIW is the most eco-friendly, low-cost solvent, and it does not retain any kind of carbon residue in the fabricated absorber, which is usually observed when using organic solvents and can be a possible limitation to device performance. In addition, alkali doping/alloying is easily achievable by spraying an alkali-dissolved aqueous solution. , For the narrow band gap solar cells ( E g = ∼1.1 eV) on a flexible SUS substrate, spraying Na/K codissolved Cu-In-Ga-S precursor solution in an air environment (in situ alkali doping/alloying) provides a PCE of 11.45% …”

High Efficiency Kesterite Solar Cells Through a Dual Treatment Approach: Improving the Quality of both Absorber Bulk and Heterojunction Interface

“…[23,30] Our group also previously achieved a PCE of 12.43% using Ag-alloyed kesterite (Cu 1-x Ag x ) 2 ZnSn(S,Se) 4 (ACZTSSe) absorbers. [31] 2) For the passivation of the heterojunction interface, wide-bandgap oxide materials have been utilized to suppress the interface recombination, which could increase J SC , V OC , and FF. [32][33][34] For example, Al 2 O 3 , [32] TiO 2 , [33] and SnO 2 [34] films have been applied to kesterite CZTSSe solar cells using atomic layer deposition (ALD), spin coating and successive ionic layer adsorption and reaction, respectively.…”