Current Status of the Open-Circuit Voltage of Kesterite CZTS Absorber Layers for Photovoltaic Applications—Part I, a Review

Abstract

Herein, based on the reviewed literature, the current marketability challenges faced by kesterite CZTS based-solar cells is addressed. A knowledge update about the attempts to reduce the open circuit voltage deficit of kesterite CZTS solar cells will be addressed, with a focus on the impact of Cu/Zn order/disorder and of Se doping. This review also presents the strengths and weaknesses of the most commercially attractive synthesis methods for synthesizing thin kesterite CZTS films for photovoltaic applications.

Long-Term Oxidation Susceptibility in Ambient Air of the Semiconductor Kesterite Cu2ZnSnS4 Nanopowders Made by Mechanochemical Synthesis Method

“…The helium density and specific surface area data for the fresh and 6-month exposed to air nanopowders are compiled in Table 2. The freshly made prekesterites have somewhat lower densities in the range 3.60-3.90 g/cm 3 compared to the respective kesterites in the range 3.91-4.30 g/cm 3 for each of the precursor systems as seen by us previously. This is consistent with the more defected structures of the raw versus annealed kesterite products.…”

“…This is consistent with the more defected structures of the raw versus annealed kesterite products. The numbers are to be related to the reference density of 4.56 g/cm 3 for kesterite [50]. A noticeable decrease of the density occurs after exposure to air of both kesterite forms reflecting the prevailing impact of the actual lower densities of the oxidation products such as of dominant quantities of CuSO 4 •5H 2 O (2.29 g/cm 3 ) and ZnSO 4 •H 2 O (3.08 g/cm 3 ) over the higher density of SnO 2 (6.95 g/cm 3 ) in smaller amounts.…”

“…The numbers are to be related to the reference density of 4.56 g/cm 3 for kesterite [50]. A noticeable decrease of the density occurs after exposure to air of both kesterite forms reflecting the prevailing impact of the actual lower densities of the oxidation products such as of dominant quantities of CuSO 4 •5H 2 O (2.29 g/cm 3 ) and ZnSO 4 •H 2 O (3.08 g/cm 3 ) over the higher density of SnO 2 (6.95 g/cm 3 ) in smaller amounts. Looking from another angle on the morphology features, the BET specific surface areas (calculated from the BET theory) [51], commonly interpreted as total surface areas, for the freshly made prekesterite and kesterite are surprisingly similar to each other being in the range 17.2-18.2 m 2 /g for the CE and MS systems whereas a bit lower values in the range 11.4-12.7 m 2 /g are determined for the CA system.…”

“…Helium densities were obtained with a Micromeritics AccuPyc 1340 pycnometer (Norcross, GA, USA). The d He values for the samples were rounded up to the nearest 0.01 g/cm 3 to show them with accuracy exceeding one standard deviation value in each case. The oxygen and hydrogen contents were directly determined with the ONH836 elemental analyzer (Leco Corporation, St. Joseph, MI, USA) using 0.01-0.02 g of a sample.…”

Electron deficiency in 2D chalcogenide NaCu4S3 with metallic properties

“…The metal chalcogenides are a broad group of inorganic materials notable for structural diversity, nonlinear optical behavior, thermoelectric properties, ion sorption, photovoltaic applications, catalysis, photonics, magnetism, and superconductivity. − Among these versatile phases, copper sulfides are of particular interest because, while possessing valuable properties, they consist of less toxic and highly naturally abundant elements. The application of these materials also relates to such important fields of industry as sustainable electric energy production and rechargeable battery energy storage. − …”