TECHNOLOGY FOCUS - IMAGING AND COMMUNICATION - Preferred Components: The photoactive layer comprises thin-film Cu(In,Ga)Se2 (CIGS), cadmium-indium-selenide (CIS) or Cu2ZnSn(S,Se)4 (CZTS-Se).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The flexible substrate is a metal, stainless steel. The stainless steel comprises aluminum (3- 3.95 wt.%), chromium (22 wt.%) and aluminum (5.8 wt.%) and iron (balance). The metal is a metal selected from aluminum, titanium, molybdenum, nickel, vanadium, chromium, silver and gold. The glass layer comprises a sodium ion source (1-25 wt.%). The sodium ion source (4-18, preferably 4-16 wt.%).    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Article: The multi-layer article further comprises: conductive layer disposed on at least a portion of the glass layer; photoactive layer disposed on the conductive layer; CdS layer disposed on the photoactive layer; and transparent conductive oxide disposed on the CdS layer. The transparent conductive oxide is selected doped zinc oxide and indium tin oxide. EXAMPLE - Tetraethylorthosilicate (3.9042 g) was dissolved in 1-butanol (5 ml) and acetic acid (5 ml) containing deionized water (0.6725 ml). The solution was refluxed for 1 hour. To this solution, was added triethylborate (0.5247 g) and tris(acetylacetonato) aluminum (0.1768 g). Separately, a sodium tetraphenyl borate (1.6553 g) solution in 1-butanol (5 ml) was prepared and mixed with the silicon, aluminum, boron precursor 1-butanol solution. The solution was stirred and 1-butanol was added until a total volume of 25 ml was achieved. The glass precursor composition was filtered through a 2 mu filter prior to coating the stainless steel substrate. The filtered glass precursor composition (0.1 ml) was rod-coated using a #20 bar on a Cheminstrument (RTM: motorized drawdown coater) at room temperature in a clean room environment (class 100). The coated substrate was then dried at room temperature for 30 seconds and at 150 degrees C for 2 minutes to form a dried glass precursor layer on the annealed stainless steel substrate. After drying, the coated substrates were fired to 500 degrees C for 2 minutes at a ramp rate of 8 degrees C/seconds using a modified Leyboldt L560 vacuum chamber outfitted with cooled quartz lamp heaters above and below the coated substrate, with an air bleed of 20 seem (total pressure 1 mTorr). Out-gassing was monitored using a residual gas analyzer. Breakdown voltage was measured with a Vitrek 944i (RTM: dielectric analyzer). The sample was sandwiched between 2 electrodes, a fixed stainless steel rod as cathode (6.35 mm diameter and 12.7 mm long) and a vertically sliding stainless steel rod as anode (6.35 mm diameter and 100 mm long). The mass of the sliding electrode (32.2 g) produced enough pressure so the anode and cathode form good electrical contact with the sample. The voltage was ramped at 100 V/s to 250 V and kept constant for 30 seconds to determine the breakdown voltage and the sustained time. The thickness was measured using a digital linear drop gauge from ONO SOKKI, model EG-225. Dielectric strength can be calculated as the breakdown voltage per unit of thickness. After firing, a 200 nm Mo coating was deposited on the fired glass layer via sputter vapor deposition.