We report highly efficient Cu2ZnSn(S,Se)4 (CZTSSe) thin films with a power conversion efficiency (PCE) of 12.3% at their surface and interface. The structural and electrical properties were locally investigated, using scanning probe microscopy and micro‐Raman scattering, to improve the performance of kesterite solar cells. Interestingly, this research reports quite different results from the conventional kesterite solar cells, owing to the observance of undesirable voids and secondary phases. Nonetheless, the solar cells exhibit a high PCE of over 12%. Thus, we probe the kesterite solar cells as a function of the depth and introduce a mechanical dimple‐etching process. The relatively low melting temperature of the pure‐metal precursors results in the unique properties within the solar cell materials. Understanding these phenomena and their effects on carrier behavior enables the achievement of a higher PCE and better performance for kesterite solar cells.

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The production of commercialized Cu(In,Ga)(S,Se) 2 (CIGS) photovoltaic absorber layers uses expensive H 2 Se gas with a high utility cost. To reduce the manufacturing cost of CIGS photovoltaic modules, a process technology capable of supplying Se vapor uniformly over a large area is required to replace H 2 Se. In this study, a nozzle-free Se shower was implemented using a porous material to pass Se vapor while confining liquid Se, and the highly effective selenization of the CuInGa precursor was performed. The nozzle-free Se-shower vehicle could be mounted in a commercial rapid thermal process chamber. The chamber pressure and the temperatures of the shower module and substrate, which were controlled independently by the upper and lower heaters, respectively, were varied to control the amount of Se supplied during the entire selenization reaction in real time. In particular, the precursor should be soaked with a sufficient amount of Se at a relatively low substrate temperature of 300°C or less to obtain a good quality absorber. In addition, at a chamber pressure of 100 Torr during the soaking stage, the Ga content in the surface region of the absorber increased considerably with a concomitant improvement in the open-circuit voltage. The highest performance obtained using this method was an open-circuit voltage of 0.638 V, short-circuit current density of 34 mA/cm 2 , fill factor of 67.2%, and an active area efficiency of 14.57%. This performance is very high compared with other CIGS solar cells manufactured by a 2-step process using Se vapor.

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This paper reports the two dimensional (2D) magnetic sensor, which is comprised of twoMOSFET Hall devices with similar characteristics. The sensor is based on the MOSFET Hall deviceprinciple and is fabricated on <100> orientation silicon substrate by adopting complementary metaloxide semiconductor (CMOS) technology and packaging technology. The experiment results indicatethat when VDS =5.0 V, the magnetic sensitivities of the 2D magnetic sensor can reach Sx=34.0 mV/Tand Sy=33.6 mV/T in the x and y directions, respectively, it is necessary to realize the measurementof 2D magnetic field.