Effects of silver-doping on properties of Cu(In,Ga)Se2 films prepared by CuInGa precursors

The Effect of Absorber Stoichiometry on the Stability of Widegap (Ag,Cu)(In,Ga)Se2Solar Cells

“…Ag, In, and Ga have very similar ionic radii, so the diffusion of Ag could lead to antisite defects. [ 19 ] Although OVCs have been deemed rather unlikely to trigger the depletion width variation, it is to be noted that even for nearly full absorber depletion, highly off‐stoichiometric devices never attain EQE spectra as high as those of the close‐stoichiometric devices, indicating that there is perhaps a reduction in carrier collection caused by OVCs that operate in parallel with the main observed effects.…”

“…[ 9,15–17 ] The incorporation of silver into CIGS, substituting some of the copper atoms, is expected to be beneficial, improving the conduction band offset between the silver‐alloyed CIGS (ACIGS) and the commonly used CdS buffer layer. [ 18 ] Silver incorporation in CIGS is also observed to increase grain size [ 19 ] and reduce the melting point of the alloy, which is expected to reduce the density of defects in the material. [ 20–22 ]…”

“…[9,[15][16][17] The incorporation of silver into CIGS, substituting some of the copper atoms, is expected to be beneficial, improving the conduction band offset between the silveralloyed CIGS (ACIGS) and the commonly used CdS buffer layer. [18] Silver incorporation in CIGS is also observed to increase grain size [19] and reduce the melting point of the alloy, which is expected to reduce the density of defects in the material. [20][21][22] With a clear motivation to investigate the incorporation of Ag into CIGS and the realization of high-performance widegap CIGS-based devices, we produced a large series of ACIGS cells, spanning a wide range of compositions.…”

Study on the Performance of Oxygen-Rich Zn(O,S) Buffers Fabricated by Sputtering Deposition and Zn(O,S)/Cu(In,Ga)(S,Se)2 Interfaces

“…The last contains a constant capacitance C n and a “capacitance-like element” described as a constant phase element (CPE) CPE j . R s characterizes the bulk resistance and contact resistance, R n and C n correspond to the interface quality of ZnO:Al/Zn­(O,S) (n–n junction), R j represents the carrier recombination resistance in the depletion region at Zn­(O,S)/CIGSSe (p–n junction), and CPE j is related to the diffusion and depletion capacitance . CPE is an impedance reflected as a collapsed semicircle whose center is below the imaginary axis.…”

Investigating the Role of Ag and Ga Content in the Stability of Wide‐Gap (Ag,Cu)(In,Ga)Se2 Thin‐Film Solar Cells

“…[9][10][11] Partial substitution of Cu with Ag can improve the conduction band offset between high-Ga (Ag,Cu)(In,Ga)Se 2 (ACIGS) and CdS [12] and through a reduction in the alloy melting temperature, ease the growth of high-quality absorber material on transparent back contacts (common processing temperatures of %550°lead to harmful GaO x formation at the interface between CIGS and transparent conducting oxide [TCO] back contacts). [13][14][15] Our group has investigated a large range of ACIGS compositions, primarily focusing on high-Ga, wide-gap material, yielding high V OC and promising efficiencies. [16] In a previous work, we discovered that wide-gap ACIGS with bandgaps around 1.45 eV exhibit strong instabilities, with a significant dependence on group-I/group-III stoichiometry (I/III), linked to a strong dependence of net doping on I/III.…”