An x-ray target, x-ray source, and x-ray system are provided. The x-ray target includes a thermally conductive substrate comprising a surface and at least one structure on or embedded in at least a portion of the surface. The at least one structure includes a thermally conductive first material in thermal communication with the substrate. The first material has a length along a first direction parallel to the portion of the surface in a range greater than 1 millimeter and a width along a second direction parallel to the portion of the surface and perpendicular to the first direction. The width is in a range of 0.2 millimeter to 3 millimeters. The at least one structure further includes at least one layer over the first material. The at least one layer includes at least one second material different from the first material. The at least one layer has a thickness in a range of 2 microns to 50 microns. The at least one second material is configured to generate x-rays upon irradiation by electrons.